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authorGravatar Benjamin Barenblat <bbaren@debian.org>2019-02-02 19:29:23 -0500
committerGravatar Benjamin Barenblat <bbaren@debian.org>2019-02-02 19:29:23 -0500
commit9ebf44d84754adc5b64fcf612c6816c02c80462d (patch)
treebf5e06a28488e0e06a2f2011ff0d110e2e02f8fc /CHANGES.md
parent9043add656177eeac1491a73d2f3ab92bec0013c (diff)
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+Changes from 8.9+beta1 to 8.9.0
+===============================
+
+Assorted bug fixes.
+
+Changes from 8.8.2 to 8.9+beta1
+===============================
+
+Kernel
+
+- Mutually defined records are now supported.
+
+Notations
+
+- New support for autonomous grammars of terms, called "custom
+ entries" (see chapter "Syntax extensions" of the reference manual).
+
+- Deprecated compatibility notations will actually be removed in the
+ next version of Coq. Uses of these notations are generally easy to
+ fix thanks to the hint contained in the deprecation warnings. For
+ projects that require more than a handful of such fixes, there is [a
+ script](https://gist.github.com/JasonGross/9770653967de3679d131c59d42de6d17#file-replace-notations-py)
+ that will do it automatically, using the output of coqc. The script
+ contains documentation on its usage in a comment at the top.
+
+Tactics
+
+- Added toplevel goal selector `!` which expects a single focused goal.
+ Use with `Set Default Goal Selector` to force focusing before tactics
+ are called.
+
+- The undocumented "nameless" forms `fix N`, `cofix` that were
+ deprecated in 8.8 have been removed from Ltac's syntax; please use
+ `fix ident N/cofix ident` to explicitly name the (co)fixpoint
+ hypothesis to be introduced.
+
+- Introduction tactics `intro`/`intros` on a goal that is an
+ existential variable now force a refinement of the goal into a
+ dependent product rather than failing.
+
+- Support for `fix`/`cofix` added in Ltac `match` and `lazymatch`.
+
+- Ltac backtraces now include trace information about tactics
+ called by OCaml-defined tactics.
+
+- Option `Ltac Debug` now applies also to terms built using Ltac functions.
+
+- Deprecated the `Implicit Tactic` family of commands.
+
+- The default program obligation tactic uses a bounded proof search
+ instead of an unbounded and potentially non-terminating one now
+ (source of incompatibility).
+
+- The `simple apply` tactic now respects the `Opaque` flag when called from
+ Ltac (`auto` still does not respect it).
+
+- Tactic `constr_eq` now adds universe constraints needed for the
+ identity to the context (it used to ignore them). New tactic
+ `constr_eq_strict` checks that the required constraints already hold
+ without adding new ones. Preexisting tactic `constr_eq_nounivs` can
+ still be used if you really want to ignore universe constraints.
+
+- Tactics and tactic notations now understand the `deprecated` attribute.
+- The `fourier` tactic has been removed. Please now use `lra` instead. You
+ may need to add `Require Import Lra` to your developments. For compatibility,
+ we now define `fourier` as a deprecated alias of `lra`.
+
+- The `romega` tactics have been deprecated; please use `lia` instead.
+
+Focusing
+
+- Focusing bracket `{` now supports named goal selectors,
+ e.g. `[x]: {` will focus on a goal (existential variable) named `x`.
+ As usual, unfocus with `}` once the sub-goal is fully solved.
+
+Specification language
+
+- A fix to unification (which was sensitive to the ascii name of
+ variables) may occasionally change type inference in incompatible
+ ways, especially regarding the inference of the return clause of `match`.
+
+Standard Library
+
+- Added `Ascii.eqb` and `String.eqb` and the `=?` notation for them,
+ and proved some lemmas about them. Note that this might cause
+ incompatibilities if you have, e.g., `string_scope` and `Z_scope` both
+ open with `string_scope` on top, and expect `=?` to refer to `Z.eqb`.
+ Solution: wrap `_ =? _` in `(_ =? _)%Z` (or whichever scope you
+ want).
+
+- Added `Ndigits.N2Bv_sized`, and proved some lemmas about it.
+ Deprecated `Ndigits.N2Bv_gen`.
+
+- The scopes `int_scope` and `uint_scope` have been renamed to
+ `dec_int_scope` and `dec_uint_scope`, to clash less with ssreflect
+ and other packages. They are still delimited by `%int` and `%uint`.
+
+- Syntax notations for `string`, `ascii`, `Z`, `positive`, `N`, `R`,
+ and `int31` are no longer available merely by `Require`ing the files
+ that define the inductives. You must `Import` `Coq.Strings.String`,
+ `Coq.Strings.Ascii`, `Coq.ZArith.BinIntDef`, `Coq.PArith.BinPosDef`,
+ `Coq.NArith.BinNatDef`, `Coq.Reals.Rdefinitions`, and
+ `Coq.Numbers.Cyclic.Int31.Int31`, respectively, to be able to use
+ these notations. Note that passing `-compat 8.8` or issuing
+ `Require Import Coq.Compat.Coq88` will make these notations
+ available. Users wishing to port their developments automatically
+ may download `fix.py` from
+ <https://gist.github.com/JasonGross/5d4558edf8f5c2c548a3d96c17820169>
+ and run a command like `while true; do make -Okj 2>&1 |
+ /path/to/fix.py; done` and get a cup of coffee. (This command must
+ be manually interrupted once the build finishes all the way though.
+ Note also that this method is not fail-proof; you may have to adjust
+ some scopes if you were relying on string notations not being
+ available even when `string_scope` was open.)
+
+- Numeral syntax for `nat` is no longer available without loading the
+ entire prelude (`Require Import Coq.Init.Prelude`). This only
+ impacts users running Coq without the init library (`-nois` or
+ `-noinit`) and also issuing `Require Import Coq.Init.Datatypes`.
+
+Tools
+
+- Coq_makefile lets one override or extend the following variables from
+ the command line: `COQFLAGS`, `COQCHKFLAGS`, `COQDOCFLAGS`.
+ `COQFLAGS` is now entirely separate from `COQLIBS`, so in custom Makefiles
+ `$(COQFLAGS)` should be replaced by `$(COQFLAGS) $(COQLIBS)`.
+
+- Removed the `gallina` utility (extracts specification from Coq vernacular files).
+ If you would like to maintain this tool externally, please contact us.
+
+- Removed the Emacs modes distributed with Coq. You are advised to
+ use [Proof-General](https://proofgeneral.github.io/) (and optionally
+ [Company-Coq](https://github.com/cpitclaudel/company-coq)) instead.
+ If your use case is not covered by these alternative Emacs modes,
+ please open an issue. We can help set up external maintenance as part
+ of Proof-General, or independently as part of coq-community.
+
+Vernacular Commands
+
+- Removed deprecated commands `Arguments Scope` and `Implicit Arguments`
+ (not the option). Use the `Arguments` command instead.
+- Nested proofs may be enabled through the option `Nested Proofs Allowed`.
+ By default, they are disabled and produce an error. The deprecation
+ warning which used to occur when using nested proofs has been removed.
+- Added option `Uniform Inductive Parameters` which abstracts over parameters
+ before typechecking constructors, allowing to write for example
+ `Inductive list (A : Type) := nil : list | cons : A -> list -> list.`
+- New `Set Hint Variables/Constants Opaque/Transparent` commands for setting
+ globally the opacity flag of variables and constants in hint databases,
+ overwritting the opacity set of the hint database.
+- Added generic syntax for "attributes", as in:
+ `#[local] Lemma foo : bar.`
+- Added the `Numeral Notation` command for registering decimal numeral
+ notations for custom types
+- The `Set SsrHave NoTCResolution` command no longer has special global
+ scope. If you want the previous behavior, use `Global Set SsrHave
+ NoTCResolution`.
+- Multiple sections with the same name are allowed.
+
+Coq binaries and process model
+
+- Before 8.9, Coq distributed a single `coqtop` binary and a set of
+ dynamically loadable plugins that used to take over the main loop
+ for tasks such as IDE language server or parallel proof checking.
+
+ These plugins have been turned into full-fledged binaries so each
+ different process has associated a particular binary now, in
+ particular `coqidetop` is the CoqIDE language server, and
+ `coq{proof,tactic,query}worker` are in charge of task-specific and
+ parallel proof checking.
+
+SSReflect
+
+- The implementation of delayed clear switches in intro patterns
+ is now simpler to explain:
+ 1. The immediate effect of a clear switch like `{x}` is to rename the
+ variable `x` to `_x_` (i.e. a reserved identifier that cannot be mentioned
+ explicitly)
+ 2. The delayed effect of `{x}` is that `_x_` is cleared at the end of the intro
+ pattern
+ 3. A clear switch immediately before a view application like `{x}/v` is
+ translated to `/v{x}`.
+
+ In particular, the third rule lets one write `{x}/v` even if `v` uses the variable `x`:
+ indeed the view is executed before the renaming.
+
+- An empty clear switch is now accepted in intro patterns before a
+ view application whenever the view is a variable.
+ One can now write `{}/v` to mean `{v}/v`. Remark that `{}/x` is very similar
+ to the idiom `{}e` for the rewrite tactic (the equation `e` is used for
+ rewriting and then discarded).
+
+Standard Library
+
+- There are now conversions between `string` and `positive`, `Z`,
+ `nat`, and `N` in binary, octal, and hex.
+
+Display diffs between proof steps
+
+- `coqtop` and `coqide` can now highlight the differences between proof steps
+ in color. This can be enabled from the command line or the
+ `Set Diffs "on"/"off"/"removed"` command. Please see the documentation for
+ details. Showing diffs in Proof General requires small changes to PG
+ (under discussion).
+
+Notations
+
+- Added `++` infix for `VectorDef.append`.
+ Note that this might cause incompatibilities if you have, e.g., `list_scope`
+ and `vector_scope` both open with `vector_scope` on top, and expect `++` to
+ refer to `app`.
+ Solution: wrap `_ ++ _` in `(_ ++ _)%list` (or whichever scope you want).
+
+Changes from 8.8.1 to 8.8.2
+===========================
+
+Documentation
+
+- A PDF version of the reference manual is available once again.
+
+Tools
+
+- The coq-makefile targets `print-pretty-timed`, `print-pretty-timed-diff`,
+ and `print-pretty-single-time-diff` now correctly label the "before" and
+ "after" columns, rather than swapping them.
+
+Kernel
+
+- The kernel does not tolerate capture of global universes by
+ polymorphic universe binders, fixing a soundness break (triggered
+ only through custom plugins)
+
+Windows installer
+
+- The Windows installer now includes many more external packages that can be
+ individually selected for installation.
+
+Many other bug fixes and lots of documentation improvements (for details,
+see the 8.8.2 milestone at https://github.com/coq/coq/milestone/15?closed=1).
+
+Changes from 8.8.0 to 8.8.1
+===========================
+
+Kernel
+
+- Fix a critical bug with cofixpoints and `vm_compute`/`native_compute` (#7333).
+- Fix a critical bug with modules and algebraic universes (#7695)
+- Fix a critical bug with inlining of polymorphic constants (#7615).
+- Fix a critical bug with universe polymorphism and `vm_compute` (#7723). Was
+ present since 8.5.
+
+Notations
+
+- Fixed unexpected collision between only-parsing and only-printing
+ notations (issue #7462).
+
+Windows installer
+
+- The Windows installer now includes external packages Ltac2 and Equations
+ (it included the Bignums package since 8.8+beta1).
+
+Many other bug fixes, documentation improvements (including fixes of
+regressions due to the Sphinx migration), and user message improvements
+(for details, see the 8.8.1 milestone at
+https://github.com/coq/coq/milestone/13?closed=1).
+
+Changes from 8.8+beta1 to 8.8.0
+===============================
+
+Tools
+
+- Asynchronous proof delegation policy was fixed. Since version 8.7
+ Coq was ignoring previous runs and the `-async-proofs-delegation-threshold`
+ option did not have the expected behavior.
+
+Tactic language
+
+- The undocumented "nameless" forms `fix N`, `cofix` have been
+ deprecated; please use `fix ident N /cofix ident` to explicitely
+ name the (co)fixpoint hypothesis to be introduced.
+
+Documentation
+
+- The reference manual is now fully ported to Sphinx.
+
+Other small deprecations and bug fixes.
+
+Changes from 8.7.2 to 8.8+beta1
+===============================
+
+Kernel
+
+- Support for template polymorphism for definitions was removed. May trigger
+ more "universe inconsistency" errors in rare occasions.
+- Fixpoints are no longer allowed on non-recursive inductive types.
+
+Notations
+
+- Recursive notations with the recursive pattern repeating on the
+ right (e.g. "( x ; .. ; y ; z )") now supported.
+- Notations with a specific level for the leftmost nonterminal,
+ when printing-only, are supported.
+- Notations can now refer to the syntactic category of patterns (as in
+ "fun 'pat =>" or "match p with pat => ... end"). Two variants are
+ available, depending on whether a single variable is considered as a
+ pattern or not.
+- Recursive notations now support ".." patterns with several
+ occurrences of the recursive term or binder, possibly mixing terms
+ and binders, possibly in reverse left-to-right order.
+- "Locate" now working also on notations of the form "x + y" (rather
+ than "_ + _").
+
+Specification language
+
+- When printing clauses of a "match", clauses with same right-hand
+ side are factorized and the last most factorized clause with no
+ variables, if it exists, is turned into a default clause.
+ Use "Unset Printing Allow Default Clause" do deactivate printing
+ of a default clause.
+ Use "Unset Printing Factorizable Match Patterns" to deactivate
+ factorization of clauses with same right-hand side.
+
+Tactics
+
+- On Linux, "native_compute" calls can be profiled using the "perf"
+ utility. The command "Set NativeCompute Profiling" enables
+ profiling, and "Set NativeCompute Profile Filename" customizes
+ the profile filename.
+- The tactic "omega" is now aware of the bodies of context variables
+ such as "x := 5 : Z" (see #1362). This could be disabled via
+ Unset Omega UseLocalDefs.
+- The tactic "romega" is also aware now of the bodies of context variables.
+- The tactic "zify" resp. "omega with N" is now aware of N.pred.
+- Tactic "decide equality" now able to manage constructors which
+ contain proofs.
+- Added tactics reset ltac profile, show ltac profile (and variants)
+- Added tactics restart_timer, finish_timing, and time_constr as an
+ experimental way of timing Ltac's evaluation phase
+- Added tactic optimize_heap, analogous to the Vernacular Optimize
+ Heap, which performs a major garbage collection and heap compaction
+ in the OCaml run-time system.
+- The tactics "dtauto", "dintuition", "firstorder" now handle inductive types
+ with let bindings in the parameters.
+- The tactic "dtauto" now handles some inductives such as
+ "@sigT A (fun _ => B)" as non-dependent conjunctions.
+- A bug fixed in "rewrite H in *" and "rewrite H in * |-" may cause a
+ few rare incompatibilities (it was unintendedly recursively
+ rewriting in the side conditions generated by H).
+- Added tactics "assert_succeeds tac" and "assert_fails tac" to ensure
+ properties of the executation of a tactic without keeping the effect
+ of the execution.
+- `vm_compute` now supports existential variables.
+- Calls to `shelve` and `give_up` within calls to tactic `refine` now working.
+- Deprecated tactic `appcontext` was removed.
+
+Focusing
+
+- Focusing bracket `{` now supports single-numbered goal selector,
+ e.g. `2: {` will focus on the second sub-goal. As usual, unfocus
+ with `}` once the sub-goal is fully solved.
+ The `Focus` and `Unfocus` commands are now deprecated.
+
+Vernacular Commands
+
+- Proofs ending in "Qed exporting ident, .., ident" are not supported
+ anymore. Constants generated during `abstract` are kept private to the
+ local environment.
+- The deprecated Coercion Local, Open Local Scope, Notation Local syntax
+ was removed. Use Local as a prefix instead.
+- For the Extraction Language command, "OCaml" is spelled correctly.
+ The older "Ocaml" is still accepted, but deprecated.
+- Using “Require” inside a section is deprecated.
+- An experimental command "Show Extraction" allows to extract the content
+ of the current ongoing proof (grant wish #4129).
+- Coercion now accepts the type of its argument to be "Prop" or "Type".
+- The "Export" modifier can now be used when setting and unsetting options, and
+ will result in performing the same change when the module corresponding the
+ command is imported.
+- The `Axiom` command does not automatically declare axioms as instances when
+ their type is a class. Previous behavior can be restored using `Set
+ Typeclasses Axioms Are Instances`.
+
+Universes
+
+- Qualified naming of global universes now works like other namespaced
+ objects (e.g. constants), with a separate namespace, inside and across
+ module and library boundaries. Global universe names introduced in an
+ inductive / constant / Let declaration get qualified with the name of
+ the declaration.
+- Universe cumulativity for inductive types is now specified as a
+ variance for each polymorphic universe. See the reference manual for
+ more information.
+- Inference of universe constraints with cumulative inductive types
+ produces more general constraints. Unsetting new option Cumulativity
+ Weak Constraints produces even more general constraints (but may
+ produce too many universes to be practical).
+- Fix #5726: Notations that start with `Type` now support universe instances
+ with `@{u}`.
+- `with Definition` now understands universe declarations
+ (like `@{u| Set < u}`).
+
+Tools
+
+- Coq can now be run with the option -mangle-names to change the auto-generated
+ name scheme. This is intended to function as a linter for developments that
+ want to be robust to changes in auto-generated names. This feature is experimental,
+ and may change or disappear without warning.
+- GeoProof support was removed.
+
+Checker
+
+- The checker now accepts filenames in addition to logical paths.
+
+CoqIDE
+
+- Find and Replace All report the number of occurrences found; Find indicates
+ when it wraps.
+
+coqdep
+
+- Learned to read -I, -Q, -R and filenames from _CoqProject files.
+ This is used by coq_makefile when generating dependencies for .v
+ files (but not other files).
+
+Documentation
+
+- The Coq FAQ, formerly located at https://coq.inria.fr/faq, has been
+ moved to the GitHub wiki section of this repository; the main entry
+ page is https://github.com/coq/coq/wiki/The-Coq-FAQ.
+- Documentation: a large community effort resulted in the migration
+ of the reference manual to the Sphinx documentation tool. The result
+ is partially integrated in this version.
+
+Standard Library
+
+- New libraries Coq.Init.Decimal, Coq.Numbers.DecimalFacts,
+ Coq.Numbers.DecimalNat, Coq.Numbers.DecimalPos,
+ Coq.Numbers.DecimalN, Coq.Numbers.DecimalZ,
+ Coq.Numbers.DecimalString providing a type of decimal numbers, some
+ facts about them, and conversions between decimal numbers and nat,
+ positive, N, Z, and string.
+- Added [Coq.Strings.String.concat] to concatenate a list of strings
+ inserting a separator between each item
+- Notation `'` for Zpos in QArith was removed.
+
+- Some deprecated aliases are now emitting warnings when used.
+
+Compatibility support
+
+- Support for compatibility with versions before 8.6 was dropped.
+
+Options
+
+- The following deprecated options have been removed:
+
+ + `Refolding Reduction`
+ + `Standard Proposition Elimination`
+ + `Dependent Propositions Elimination`
+ + `Discriminate Introduction`
+ + `Shrink Abstract`
+ + `Tactic Pattern Unification`
+ + `Intuition Iff Unfolding`
+ + `Injection L2R Pattern Order`
+ + `Record Elimination Schemes`
+ + `Match Strict`
+ + `Tactic Compat Context`
+ + `Typeclasses Legacy Resolution`
+ + `Typeclasses Module Eta`
+ + `Typeclass Resolution After Apply`
+
+Changes from 8.7.1 to 8.7.2
+===========================
+
+Fixed a critical bug in the VM handling of universes (#6677). This bug
+affected all releases since 8.5.
+
+Improved support for building with OCaml 4.06.0 and external num package.
+
+Many other bug fixes, documentation improvements, and user
+message improvements (for details, see the 8.7.2 milestone at
+https://github.com/coq/coq/milestone/11?closed=1).
+
+Changes from 8.7.0 to 8.7.1
+===========================
+
+Compatibility with OCaml 4.06.0.
+
+Many bug fixes, documentation improvements, and user message improvements (for
+details see the 8.7.1 milestone at https://github.com/coq/coq/milestone/10?closed=1).
+
+Changes from 8.7+beta2 to 8.7.0
+===============================
+
+OCaml
+
+- Users can pass specific flags to the OCaml optimizing compiler by
+ -using the flambda-opts configure-time option.
+
+ Beware that compiling Coq with a flambda-enabled compiler is
+ experimental and may require large amounts of RAM and CPU, see
+ INSTALL for more details.
+
+Changes from 8.7+beta1 to 8.7+beta2
+===================================
+
+Tools
+
+- In CoqIDE, the "Compile Buffer" command takes account of flags in
+ _CoqProject or other project file.
+
+Improvements around some error messages.
+
+Many bug fixes including two important ones:
+
+- Bug #5730: CoqIDE becomes unresponsive on file open.
+- coq_makefile: make sure compile flags for Coq and coq_makefile are in sync
+ (in particular, make sure the `-safe-string` option is used to compile plugins).
+
+Changes from 8.6.1 to 8.7+beta1
+===============================
+
+Tactics
+
+- New tactic "extensionality in H" which applies (possibly dependent)
+ functional extensionality in H supposed to be a quantified equality
+ until giving a bare equality.
+- New tactic "inversion_sigma" which turns equalities of dependent
+ pairs (e.g., "existT P x p = existT P y q", frequently left over by
+ "inversion" on a dependent type family) into pairs of equalities
+ (e.g., a hypothesis "H : x = y" and a hypothesis of type "rew H in p
+ = q"); these hypotheses can subsequently be simplified using
+ "subst", without ever invoking any kind of axiom asserting
+ uniqueness of identity proofs. If you want to explicitly specify the
+ hypothesis to be inverted, or name the generated hypotheses, you can
+ invoke "induction H as [H1 H2] using eq_sigT_rect". The tactic also
+ works for "sig", "sigT2", and "sig2", and there are similar
+ "eq_sig*_rect" induction lemmas.
+- Tactic "specialize with ..." now accepts any partial bindings.
+ Missing bindings are either solved by unification or left quantified
+ in the hypothesis.
+- New representation of terms that statically ensure stability by
+ evar-expansion. This has several consequences.
+ * In terms of performance, this adds a cost to every term destructuration,
+ but at the same time most eager evar normalizations were removed, which
+ couterbalances this drawback and even sometimes outperforms the old
+ implementation. For instance, many operations that would require O(n)
+ normalization of the term are now O(1) in tactics. YMMV.
+ * This triggers small changes in unification, which was not evar-insensitive.
+ Most notably, the new implementation recognizes Miller patterns that were
+ missed before because of a missing normalization step. Hopefully this should
+ be fairly uncommon.
+- Tactic "auto with real" can now discharge comparisons of literals.
+- The types of variables in patterns of "match" are now
+ beta-iota-reduced after type-checking. This has an impact on the
+ type of the variables that the tactic "refine" introduces in the
+ context, producing types a priori closer to the expectations.
+- In "Tactic Notation" or "TACTIC EXTEND", entry "constr_with_bindings"
+ now uses type classes and rejects terms with unresolved holes, like
+ entry "constr" does. To get the former behavior use
+ "open_constr_with_bindings" (possible source of incompatibility).
+- New e-variants eassert, eenough, epose proof, eset, eremember, epose
+ which behave like the corresponding variants with no "e" but turn
+ unresolved implicit arguments into existential variables, on the
+ shelf, rather than failing.
+- Tactic injection has become more powerful (closes bug #4890) and its
+ documentation has been updated.
+- New variants of the `first` and `solve` tacticals that do not rely
+ on parsing rules, meant to define tactic notations.
+- Added support for side effects hooks in `cbv`, `cbn` and `simpl`.
+ The side effects are provided via a plugin:
+ https://github.com/herbelin/reduction-effects/
+- It is now possible to take hint database names as parameters in a
+ Ltac definition or a Tactic Notation.
+- New option `Set Ltac Batch Debug` on top of `Set Ltac Debug` for
+ non-interactive Ltac debug output.
+
+Gallina
+
+- Now supporting all kinds of binders, including 'pat, in syntax of record fields.
+
+Vernacular Commands
+
+- Goals context can be printed in a more compact way when `Set
+ Printing Compact Contexts` is activated.
+- Unfocused goals can be printed with the `Set Printing Unfocused`
+ option.
+- `Print` now shows the types of let-bindings.
+- The compatibility options for printing primitive projections
+ (`Set Printing Primitive Projection Parameters` and
+ `Set Printing Primitive Projection Compatibility`) are now off by default.
+- Possibility to unset the printing of notations in a more fine grained
+ fashion than `Unset Printing Notations` is provided without any
+ user-syntax. The goal is that someone creates a plugin to experiment
+ such a user-syntax, to be later integrated in Coq when stabilized.
+- `About` now tells if a reference is a coercion.
+- The deprecated `Save` vernacular and its form `Save Theorem id` to
+ close proofs have been removed from the syntax. Please use `Qed`.
+- `Search` now sorts results by relevance (the relevance metric is a
+ weighted sum of number of distinct symbols and size of the term).
+
+Standard Library
+
+- New file PropExtensionality.v to explicitly work in the axiomatic
+ context of propositional extensionality.
+- New file SetoidChoice.v axiomatically providing choice over setoids,
+ and, consequently, choice of representatives in equivalence classes.
+ Various proof-theoretic characterizations of choice over setoids in
+ file ChoiceFacts.v.
+- New lemmas about iff and about orders on positive and Z.
+- New lemmas on powerRZ.
+- Strengthened statement of JMeq_eq_dep (closes bug #4912).
+- The BigN, BigZ, BigZ libraries are no longer part of the Coq standard
+ library, they are now provided by a separate repository
+ https://github.com/coq/bignums
+ The split has been done just after the Int31 library.
+
+- IZR (Reals) has been changed to produce a compact representation of
+ integers. As a consequence, IZR is no longer convertible to INR and
+ lemmas such as INR_IZR_INZ should be used instead.
+- Real constants are now represented using IZR rather than R0 and R1;
+ this might cause rewriting rules to fail to apply to constants.
+- Added new notation {x & P} for sigT (without a type for x)
+
+Plugins
+
+- The Ssreflect plugin is now distributed with Coq. Its documentation has
+ been integrated as a chapter of the reference manual. This chapter is
+ work in progress so feedback is welcome.
+- The mathematical proof language (also known as declarative mode) was removed.
+- A new command Extraction TestCompile has been introduced, not meant
+ for the general user but instead for Coq's test-suite.
+- The extraction plugin is no longer loaded by default. It must be
+ explicitly loaded with [Require Extraction], which is backwards
+ compatible.
+- The functional induction plugin (which provides the [Function]
+ vernacular) is no longer loaded by default. It must be explicitly
+ loaded with [Require FunInd], which is backwards compatible.
+
+
+Dependencies
+
+- Support for camlp4 has been removed.
+
+Tools
+
+- coq_makefile was completely redesigned to improve its maintainability and
+ the extensibility of generated Makefiles, and to make _CoqProject files
+ more palatable to IDEs. Overview:
+ * _CoqProject files contain only Coq specific data (i.e. the list of
+ files, -R options, ...)
+ * coq_makefile translates _CoqProject to Makefile.conf and copies in the
+ desired location a standard Makefile (that reads Makefile.conf)
+ * Makefile extensions can be implemented in a Makefile.local file (read
+ by the main Makefile) by installing a hook in the extension points
+ provided by the standard Makefile
+ The current version contains code for retro compatibility that prints
+ warnings when a deprecated feature is used. Please upgrade your _CoqProject
+ accordingly.
+ * Additionally, coq_makefile-made Makefiles now support experimental timing
+ targets `pretty-timed`, `pretty-timed-before`, `pretty-timed-after`,
+ `print-pretty-timed-diff`, `print-pretty-single-time-diff`,
+ `all.timing.diff`, and the variable `TIMING=1` (or `TIMING=before` or
+ `TIMING=after`); see the documentation for more details.
+
+Build Infrastructure
+
+- Note that 'make world' does not build the bytecode binaries anymore.
+ For that, you can use 'make byte' (and 'make install-byte' afterwards).
+ Warning: native and byte compilations should *not* be mixed in the same
+ instance of 'make -j', otherwise both ocamlc and ocamlopt might race for
+ access to the same .cmi files. In short, use "make -j && make -j byte"
+ instead of "make -j world byte".
+
+Universes
+
+- Cumulative inductive types. see prefixes "Cumulative", "NonCumulative"
+ for inductive definitions and the option "Set Polymorphic Inductive Cumulativity"
+ in the reference manual.
+- New syntax `foo@{_}` to instantiate a polymorphic definition with
+ anonymous universes (can also be used with `Type`).
+
+XML Protocol and internal changes
+
+See dev/doc/changes.txt
+
+Many bugfixes including #1859, #2884, #3613, #3943, #3994,
+#4250, #4709, #4720, #4824, #4844, #4911, #5026, #5233,
+#5275, #5315, #5336, #5360, #5390, #5414, #5417, #5420,
+#5439, #5449, #5475, #5476, #5482, #5501, #5507, #5520,
+#5523, #5524, #5553, #5577, #5578, #5589, #5597, #5598,
+#5607, #5618, #5619, #5620, #5641, #5648, #5651, #5671.
+
+Many bugfixes on OS X and Windows (now the test-suite passes on these
+platforms too).
+
+Many optimizations.
+
+Many documentation improvements.
+
+Changes from 8.6 to 8.6.1
+=========================
+
+- Fix #5380: Default colors for CoqIDE are actually applied.
+- Fix plugin warnings
+- Document named evars (including Show ident)
+- Fix Bug #5574, document function scope
+- Adding a test case as requested in bug 5205.
+- Fix Bug #5568, no dup notation warnings on repeated module imports
+- Fix documentation of Typeclasses eauto :=
+- Refactor documentation of records.
+- Protecting from warnings while compiling 8.6
+- Fixing an inconsistency between configure and configure.ml
+- Add test-suite checks for coqchk with constraints
+- Fix bug #5019 (looping zify on dependent types)
+- Fix bug 5550: "typeclasses eauto with" does not work with section variables.
+- Bug 5546, qualify datatype constructors when needed in Show Match
+- Bug #5535, test for Show with -emacs
+- Fix bug #5486, don't reverse ids in tuples
+- Fixing #5522 (anomaly with free vars of pat)
+- Fix bug #5526, don't check for nonlinearity in notation if printing only
+- Fix bug #5255
+- Fix bug #3659: -time should understand multibyte encodings.
+- FIx bug #5300: Anomaly: Uncaught exception Not_found" in "Print Assumptions".
+- Fix outdated description in RefMan.
+- Repairing `Set Rewriting Schemes`
+- Fixing #5487 (v8.5 regression on ltac-matching expressions with evars).
+- Fix description of command-line arguments for Add (Rec) LoadPath
+- Fix bug #5377: @? patterns broken.
+- add XML protocol doc
+- Fix anomaly when doing [all:Check _.] during a proof.
+- Correction of bug #4306
+- Fix #5435: [Eval native_compute in] raises anomaly.
+- Instances should obey universe binders even when defined by tactics.
+- Intern names bound in match patterns
+- funind: Ignore missing info for current function
+- Do not typecheck twice the type of opaque constants.
+- show unused intro pattern warning
+- [future] Be eager when "chaining" already resolved future values.
+- Opaque side effects
+- Fix #5132: coq_makefile generates incorrect install goal
+- Run non-tactic comands without resilient_command
+- Univs: fix bug #5365, generation of u+k <= v constraints
+- make `emit' tail recursive
+- Don't require printing-only notation to be productive
+- Fix the way setoid_rewrite handles bindings.
+- Fix for bug 5244 - set printing width ignored when given enough space
+- Fix bug 4969, autoapply was not tagging shelved subgoals correctly
+
+Changes from V8.6beta1 to V8.6
+==============================
+
+Kernel
+
+- Fixed critical bug #5248 in VM long multiplication on 32-bit
+ architectures. Was there only since 8.6beta1, so no stable release impacted.
+
+Other bug fixes in universes, type class shelving,...
+
+Changes from V8.5 to V8.6beta1
+==============================
+
+Kernel
+
+- A new, faster state-of-the-art universe constraint checker.
+
+Specification language
+
+- Giving implicit arguments explicitly to a constant with multiple
+ choices of implicit arguments does not break any more insertion of
+ further maximal implicit arguments.
+- Ability to put any pattern in binders, prefixed by quote, e.g.
+ "fun '(a,b) => ...", "λ '(a,(b,c)), ...", "Definition foo '(x,y) := ...".
+ It expands into a "let 'pattern := ..."
+
+Tactics
+
+- Flag "Bracketing Last Introduction Pattern" is now on by default.
+- Flag "Regular Subst Tactic" is now on by default: it respects the
+ initial order of hypothesis, it contracts cycles, it unfolds no
+ local definitions (common source of incompatibilities, fixable by
+ "Unset Regular Subst Tactic").
+- New flag "Refolding Reduction", now disabled by default, which turns
+ on refolding of constants/fixpoints (as in cbn) during the reductions
+ done during type inference and tactic retyping. Can be extremely
+ expensive. When set off, this recovers the 8.4 behaviour of unification
+ and type inference. Potential source of incompatibility with 8.5 developments
+ (the option is set on in Compat/Coq85.v).
+- New flag "Shrink Abstract" that minimalizes proofs generated by the abstract
+ tactical w.r.t. variables appearing in the body of the proof.
+ On by default and deprecated. Minor source of incompatibility
+ for code relying on the precise arguments of abstracted proofs.
+- Serious bugs are fixed in tactic "double induction" (source of
+ incompatibilities as soon as the inductive types have dependencies in
+ the type of their constructors; "double induction" remains however
+ deprecated).
+- In introduction patterns of the form (pat1,...,patn), n should match
+ the exact number of hypotheses introduced (except for local definitions
+ for which pattern can be omitted, as in regular pattern-matching).
+- Tactic scopes in Ltac like constr: and ltac: now require parentheses around
+ their argument.
+- Every generic argument type declares a tactic scope of the form "name:(...)"
+ where name is the name of the argument. This generalizes the constr: and ltac:
+ instances.
+- When in strict mode (i.e. in a Ltac definition), if the "intro" tactic is
+ given a free identifier, it is not bound in subsequent tactics anymore.
+ In order to introduce a binding, use e.g. the "fresh" primitive instead
+ (potential source of incompatibilities).
+- New tactics is_ind, is_const, is_proj, is_constructor for use in Ltac.
+- New goal selectors. Sets of goals can be selected by listing integers
+ ranges. Example: "1,4-7,24: tac" focuses "tac" on goals 1,4,5,6,7,24.
+- For uniformity with "destruct"/"induction" and for a more natural
+ behavior, "injection" can now work in place by activating option
+ "Structural Injection". In this case, hypotheses are also put in the
+ context in the natural left-to-right order and the hypothesis on
+ which injection applies is cleared.
+- Tactic "contradiction" (hence "easy") now also solve goals with
+ hypotheses of the form "~True" or "t<>t" (possible source of
+ incompatibilities because of more successes in automation, but
+ generally a more intuitive strategy).
+- Option "Injection On Proofs" was renamed "Keep Proof Equalities". When
+ enabled, injection and inversion do not drop equalities between objects
+ in Prop. Still disabled by default.
+- New tactics "notypeclasses refine" and "simple notypeclasses refine" that
+ disallow typeclass resolution when typechecking their argument, for use
+ in typeclass hints.
+- Integration of LtacProf, a profiler for Ltac.
+- Reduction tactics now accept more fine-grained flags: iota is now a shorthand
+ for the new flags match, fix and cofix.
+- The ssreflect subterm selection algorithm is now accessible to tactic writers
+ through the ssrmatching plugin.
+- When used as an argument of an ltac function, "auto" without "with"
+ nor "using" clause now correctly uses only the core hint database by
+ default.
+
+Hints
+
+- Revised the syntax of [Hint Cut] to follow standard notation for regexps.
+- Hint Mode now accepts "!" which means that the mode matches only if the
+ argument's head is not an evar (it goes under applications, casts, and
+ scrutinees of matches and projections).
+- Hints can now take an optional user-given pattern, used only by
+ [typeclasses eauto] with the [Filtered Unification] option on.
+
+Typeclasses
+
+- Many new options and new engine based on the proof monad. The
+ [typeclasses eauto] tactic is now a multi-goal, multi-success tactic.
+ See reference manual for more information. It is planned to
+ replace auto and eauto in the following version. The 8.5 resolution
+ engine is still available to help solve compatibility issues.
+
+Program
+
+- The "Shrink Obligations" flag now applies to all obligations, not only
+ those solved by the automatic tactic.
+- "Shrink Obligations" is on by default and deprecated. Minor source of
+ incompatibility for code relying on the precise arguments of
+ obligations.
+
+Notations
+
+- "Bind Scope" can once again bind "Funclass" and "Sortclass".
+
+General infrastructure
+
+- New configurable warning system which can be controlled with the vernacular
+ command "Set Warnings", or, under coqc/coqtop, with the flag "-w". In
+ particular, the default is now that warnings are printed by coqc.
+- In asynchronous mode, Coq is now capable of recovering from errors and
+ continue processing the document.
+
+Tools
+
+- coqc accepts a -o option to specify the output file name
+- coqtop accepts --print-version to print Coq and OCaml versions in
+ easy to parse format
+- Setting [Printing Dependent Evars Line] can be unset to disable the
+ computation associated with printing the "dependent evars: " line in
+ -emacs mode
+- Removed the -verbose-compat-notations flag and the corresponding Set
+ Verbose Compat vernacular, since these warnings can now be silenced or
+ turned into errors using "-w".
+
+XML protocol
+
+- message format has changed, see dev/doc/changes.txt for more details.
+
+Many bug fixes, minor changes and documentation improvements are not mentioned
+here.
+
+Changes from V8.5pl2 to V8.5pl3
+===============================
+
+Critical bugfix
+
+- #4876: Guard checker incompleteness when using primitive projections
+
+Other bugfixes
+
+- #4780: Induction with universe polymorphism on was creating ill-typed terms.
+- #4673: regression in setoid_rewrite, unfolding let-ins for type unification.
+- #4754: Regression in setoid_rewrite, allow postponed unification problems to remain.
+- #4769: Anomaly with universe polymorphic schemes defined inside sections.
+- #3886: Program: duplicate obligations of mutual fixpoints.
+- #4994: Documentation typo.
+- #5008: Use the "md5" command on OpenBSD.
+- #5007: Do not assume the "TERM" environment variable is always set.
+- #4606: Output a break before a list only if there was an empty line.
+- #5001: metas not cleaned properly in clenv_refine_in.
+- #2336: incorrect glob data for module symbols (bug #2336).
+- #4832: Remove extraneous dot in error message.
+- Anomaly in printing a unification error message.
+- #4947: Options which take string arguments are not backwards compatible.
+- #4156: micromega cache files are now hidden files.
+- #4871: interrupting par:abstract kills coqtop.
+- #5043: [Admitted] lemmas pick up section variables.
+- Fix name of internal refine ("simple refine").
+- #5062: probably a typo in Strict Proofs mode.
+- #5065: Anomaly: Not a proof by induction.
+- Restore native compiler optimizations, they were disabled since 8.5!
+- #5077: failure on typing a fixpoint with evars in its type.
+- Fix recursive notation bug.
+- #5095: non relevant too strict test in let-in abstraction.
+- Ensuring that the evar name is preserved by "rename".
+- #4887: confusion between using and with in documentation of firstorder.
+- Bug in subst with let-ins.
+- #4762: eauto weaker than auto.
+- Remove if_then_else (was buggy). Use tryif instead.
+- #4970: confusion between special "{" and non special "{{" in notations.
+- #4529: primitive projections unfolding.
+- #4416: Incorrect "Error: Incorrect number of goals".
+- #4863: abstract in typeclass hint fails.
+- #5123: unshelve can impact typeclass resolution
+- Fix a collision about the meta-variable ".." in recursive notations.
+- Fix printing of info_auto.
+- #3209: Not_found due to an occur-check cycle.
+- #5097: status of evars refined by "clear" in ltac: closed wrt evars.
+- #5150: Missing dependency of the test-suite subsystems in prerequisite.
+- Fix a bug in error printing of unif constraints
+- #3941: Do not stop propagation of signals when Coq is busy.
+- #4822: Incorrect assertion in cbn.
+- #3479 parsing of "{" and "}" when a keyword starts with "{" or "}".
+- #5127: Memory corruption with the VM.
+- #5102: bullets parsing broken by calls to parse_entry.
+
+Various documentation improvements
+
+
+Changes from V8.5pl1 to V8.5pl2
+===============================
+
+Critical bugfix
+- Checksums of .vo files dependencies were not correctly checked.
+- Unicode-to-ASCII translation was not injective, leading in a soundness bug in
+ the native compiler.
+
+Other bugfixes
+
+- #4097: more efficient occur-check in presence of primitive projections
+- #4398: type_scope used consistently in "match goal".
+- #4450: eauto does not work with polymorphic lemmas
+- #4677: fix alpha-conversion in notations needing eta-expansion.
+- Fully preserve initial order of hypotheses in "Regular Subst Tactic" mode.
+- #4644: a regression in unification.
+- #4725: Function (Error: Conversion test raised an anomaly) and Program
+ (Error: Cannot infer this placeholder of type)
+- #4747: Problem building Coq 8.5pl1 with OCaml 4.03.0: Fatal warnings
+- #4752: CoqIDE crash on files not ended by ".v".
+- #4777: printing inefficiency with implicit arguments
+- #4818: "Admitted" fails due to undefined universe anomaly after calling
+ "destruct"
+- #4823: remote counter: avoid thread race on sockets
+- #4841: -verbose flag changed semantics in 8.5, is much harder to use
+- #4851: [nsatz] cannot handle duplicated hypotheses
+- #4858: Anomaly: Uncaught exception Failure("hd"). Please report. in variant
+ of nsatz
+- #4880: [nsatz_compute] generates invalid certificates if given redundant
+ hypotheses
+- #4881: synchronizing "Declare Implicit Tactic" with backtrack.
+- #4882: anomaly with Declare Implicit Tactic on hole of type with evars
+- Fix use of "Declare Implicit Tactic" in refine.
+ triggered by CoqIDE
+- #4069, #4718: congruence fails when universes are involved.
+
+Universes
+- Disallow silently dropping universe instances applied to variables
+ (forward compatible)
+- Allow explicit universe instances on notations, when they can apply
+ to the head reference of their expansion.
+
+Build infrastructure
+- New update on how to find camlp5 binary and library at configure time.
+
+Changes from V8.5 to V8.5pl1
+============================
+
+Critical bugfix
+- The subterm relation for the guard condition was incorrectly defined on
+ primitive projections (#4588)
+
+Plugin development tools
+- add a .merlin target to the makefile
+
+Various performance improvements (time, space used by .vo files)
+
+Other bugfixes
+
+- Fix order of arguments to Big.compare_case in ExtrOcamlZBigInt.v
+- Added compatibility coercions from Specif.v which were present in Coq 8.4.
+- Fixing a source of inefficiency and an artificial dependency in the printer in the congruence tactic.
+- Allow to unset the refinement mode of Instance in ML
+- Fixing an incorrect use of prod_appvect on a term which was not a product in setoid_rewrite.
+- Add -compat 8.4 econstructor tactics, and tests
+- Add compatibility Nonrecursive Elimination Schemes
+- Fixing the "No applicable tactic" non informative error message regression on apply.
+- Univs: fix get_current_context (bug #4603, part I)
+- Fix a bug in Program coercion code
+- Fix handling of arity of definitional classes.
+- #4630: Some tactics are 20x slower in 8.5 than 8.4.
+- #4627: records with no declared arity can be template polymorphic.
+- #4623: set tactic too weak with universes (regression)
+- Fix incorrect behavior of CS resolution
+- #4591: Uncaught exception in directory browsing.
+- CoqIDE is more resilient to initialization errors.
+- #4614: "Fully check the document" is uninterruptable.
+- Try eta-expansion of records only on non-recursive ones
+- Fix bug when a sort is ascribed to a Record
+- Primitive projections: protect kernel from erroneous definitions.
+- Fixed bug #4533 with previous Keyed Unification commit
+- Win: kill unreliable hence do not waitpid after kill -9 (Close #4369)
+- Fix strategy of Keyed Unification
+- #4608: Anomaly "output_value: abstract value (outside heap)".
+- #4607: do not read native code files if native compiler was disabled.
+- #4105: poor escaping in the protocol between CoqIDE and coqtop.
+- #4596: [rewrite] broke in the past few weeks.
+- #4533 (partial): respect declared global transparency of projections in unification.ml
+- #4544: Backtrack on using full betaiota reduction during keyed unification.
+- #4540: CoqIDE bottom progress bar does not update.
+- Fix regression from 8.4 in reflexivity
+- #4580: [Set Refine Instance Mode] also used for Program Instance.
+- #4582: cannot override notation [ x ]. MAY CREATE INCOMPATIBILITIES, see #4683.
+- STM: Print/Extraction have to be skipped if -quick
+- #4542: CoqIDE: STOP button also stops workers
+- STM: classify some variants of Instance as regular `Fork nodes.
+- #4574: Anomaly: Uncaught exception Invalid_argument("splay_arity").
+- Do not give a name to anonymous evars anymore. See bug #4547.
+- STM: always stock in vio files the first node (state) of a proof
+- STM: not delegate proofs that contain Vernac(Module|Require|Import), #4530
+- Don't fail fatally if PATH is not set.
+- #4537: Coq 8.5 is slower in typeclass resolution.
+- #4522: Incorrect "Warning..." on windows.
+- #4373: coqdep does not know about .vio files.
+- #3826: "Incompatible module types" is uninformative.
+- #4495: Failed assertion in metasyntax.ml.
+- #4511: evar tactic can create non-typed evars.
+- #4503: mixing universe polymorphic and monomorphic variables and definitions in sections is unsupported.
+- #4519: oops, global shadowed local universe level bindings.
+- #4506: Anomaly: File "pretyping/indrec.ml", line 169, characters 14-20: Assertion failed.
+- #4548: Coqide crashes when going back one command
+
+Changes from V8.5beta3 to V8.5
+==============================
+
+Tools
+
+- Flag "-compat 8.4" now loads Coq.Compat.Coq84. The standard way of
+ putting Coq in v8.4 compatibility mode is to pass the command line flag
+ "-compat 8.4". It can be followed by "-require Coq.Compat.AdmitAxiom"
+ if the 8.4 behavior of admit is needed, in which case it uses an axiom.
+
+Specification language
+
+- Syntax "$(tactic)$" changed to "ltac:(tactic)".
+
+Tactics
+
+- Syntax "destruct !hyp" changed to "destruct (hyp)", and similarly
+ for induction (rare source of incompatibilities easily solvable by
+ removing parentheses around "hyp" when not for the purpose of keeping
+ the hypothesis).
+- Syntax "p/c" for on-the-fly application of a lemma c before
+ introducing along pattern p changed to p%c1..%cn. The feature and
+ syntax are in experimental stage.
+- "Proof using" does not clear unused section variables.
+- Tactic "refine" has been changed back to the 8.4 behavior of shelving subgoals
+ that occur in other subgoals. The "refine" tactic of 8.5beta3 has been
+ renamed "simple refine"; it does not shelve any subgoal.
+- New tactical "unshelve tac" which grab existential variables put on
+ the tactic shelve by the execution of "tac".
+
+Changes from V8.5beta2 to V8.5beta3
+===================================
+
+Vernacular commands
+
+- New command "Redirect" to redirect the output of a command to a file.
+- New command "Undelimit Scope" to remove the delimiter of a scope.
+- New option "Strict Universe Declaration", set by default. It enforces the
+ declaration of all polymorphic universes appearing in a definition when
+ introducing it.
+- New command "Show id" to show goal named id.
+- Option "Virtual Machine" removed.
+
+Tactics
+
+- New flag "Regular Subst Tactic" which fixes "subst" in situations where
+ it failed to substitute all substitutable equations or failed to simplify
+ cycles, or accidentally unfolded local definitions (flag is off by default).
+- New flag "Loose Hint Behavior" to handle hints loaded but not imported in a
+ special way. It accepts three distinct flags:
+ * "Lax", which is the default one, sets the old behavior, i.e. a non-imported
+ hint behaves the same as an imported one.
+ * "Warn" outputs a warning when a non-imported hint is used. Note that this is
+ an over-approximation, because a hint may be triggered by an eauto run that
+ will eventually fail and backtrack.
+ * "Strict" changes the behavior of an unloaded hint to the one of the fail
+ tactic, allowing to emulate the hopefully future import-scoped hint mechanism.
+- New compatibility flag "Universal Lemma Under Conjunction" which
+ let tactics working under conjunctions apply sublemmas of the form
+ "forall A, ... -> A".
+- New compatibility flag "Bracketing Last Introduction Pattern" which can be
+ set so that the last disjunctive-conjunctive introduction pattern given to
+ "intros" automatically complete the introduction of its subcomponents, as the
+ the disjunctive-conjunctive introduction patterns in non-terminal position
+ already do.
+- New flag "Shrink Abstract" that minimalizes proofs generated by the abstract
+ tactical w.r.t. variables appearing in the body of the proof.
+
+Program
+
+- The "Shrink Obligations" flag now applies to all obligations, not only those
+solved by the automatic tactic.
+- Importing Program no longer overrides the "exists" tactic (potential source
+ of incompatibilities).
+- Hints costs are now correctly taken into account (potential source of
+ incompatibilities).
+- Documented the Hint Cut command that allows control of the
+ proof-search during typeclass resolution (see reference manual).
+
+API
+
+- Some functions from pretyping/typing.ml and their derivatives were potential
+ source of evarmap leaks, as they dropped their resulting evarmap. The
+ situation was clarified by renaming them according to a unsafe_* scheme. Their
+ sound variant is likewise renamed to their old name. The following renamings
+ were made.
+ * Typing.type_of -> unsafe_type_of
+ * Typing.e_type_of -> type_of
+ * A new e_type_of function that matches the e_ prefix policy
+ * Tacmach.pf_type_of -> pf_unsafe_type_of
+ * A new safe pf_type_of function.
+ All uses of unsafe_* functions should be eventually eliminated.
+
+Tools
+
+- Added an option -w to control the output of coqtop warnings.
+- Configure now takes an optional -native-compiler (yes|no) flag replacing
+ -no-native-compiler. The new flag is set to no by default under Windows.
+- Flag -no-native-compiler was removed and became the default for coqc. If
+ precompilation of files for native conversion test is desired, use
+ -native-compiler.
+- The -compile command-line option now takes the full path of the considered
+ file, including the ".v" extension, and outputs a warning if such an extension
+ is lacking.
+- The -require and -load-vernac-object command-line options now take a logical
+ path of a given library rather than a physical path, thus they behave like
+ Require [Import] path.
+- The -vm command-line option has been removed.
+
+Standard Library
+
+ - There is now a Coq.Compat.Coq84 library, which sets the various compatibility
+ options and does a few redefinitions to make Coq behave more like Coq v8.4.
+ The standard way of putting Coq in v8.4 compatibility mode is to pass the command
+ line flags "-require Coq.Compat.Coq84 -compat 8.4".
+
+Changes from V8.5beta1 to V8.5beta2
+===================================
+
+Logic
+
+- The VM now supports inductive types with up to 8388851 non-constant
+ constructors and up to 8388607 constant ones.
+
+Specification language
+
+- Syntax "$(tactic)$" changed to "ltac: tactic".
+
+Tactics
+
+- A script using the admit tactic can no longer be concluded by either
+ Qed or Defined. In the first case, Admitted can be used instead. In
+ the second case, a subproof should be used.
+- The easy tactic and the now tactical now have a more predictable
+ behavior, but they might now discharge some previously unsolved goals.
+
+Extraction
+
+- Definitions extracted to Haskell GHC should no longer randomly
+ segfault when some Coq types cannot be represented by Haskell types.
+- Definitions can now be extracted to Json for post-processing.
+
+Tools
+
+- Option -I -as has been removed, and option -R -as has been
+ deprecated. In both cases, option -R can be used instead.
+- coq_makefile now generates double-colon rules for rules such as clean.
+
+API
+
+- The interface of [change] has changed to take a [change_arg], which
+ can be built from a [constr] using [make_change_arg].
+
+Changes from V8.4 to V8.5beta1
+==============================
+
+Logic
+
+- Primitive projections for records allow for a compact representation
+ of projections, without parameters and avoid the behavior of defined
+ projections that can unfold to a case expression. To turn the use of
+ native projections on, use [Set Primitive Projections]. Record,
+ Class and Structure types defined while this option is set will be
+ defined with primitive projections instead of the usual encoding as
+ a case expression. For compatibility, when p is a primitive
+ projection, @p can be used to refer to the projection with explicit
+ parameters, i.e. [@p] is definitionally equal to [λ params r. r.(p)].
+ Records with primitive projections have eta-conversion, the
+ canonical form being [mkR pars (p1 t) ... (pn t)].
+- New universe polymorphism (see reference manual)
+- New option -type-in-type to collapse the universe hierarchy (this makes the
+ logic inconsistent).
+- The guard condition for fixpoints is now a bit stricter. Propagation
+ of subterm value through pattern matching is restricted according to
+ the return predicate. Restores compatibility of Coq's logic with the
+ propositional extensionality axiom. May create incompatibilities in
+ recursive programs heavily using dependent types.
+- Trivial inductive types are no longer defined in Type but in Prop, which
+ leads to a non-dependent induction principle being generated in place of
+ the dependent one. To recover the old behavior, explicitly define your
+ inductive types in Set.
+
+Vernacular commands
+
+- A command "Variant" allows to define non-recursive variant types.
+- The command "Record foo ..." does not generate induction principles
+ (foo_rect, foo_rec, foo_ind) anymore by default (feature wish
+ #2693). The command "Variant foo ..." does not either. A flag
+ "Set/Unset Nonrecursive Elimination Schemes" allows changing this.
+ The tactic "induction" on a "Record" or a "Variant" is now actually
+ doing "destruct".
+- The "Open Scope" command can now be given also a delimiter (e.g. Z).
+- The "Definition" command now allows the "Local" modifier, allowing
+ for non-importable definitions. The same goes for "Axiom" and "Parameter".
+- Section-specific commands such as "Let" (resp. "Variable", "Hypothesis") used
+ out of a section now behave like the corresponding "Local" command, i.e.
+ "Local Definition" (resp. "Local Parameter", "Local Axiom"). (potential source
+ of rare incompatibilities).
+- The "Let" command can now define local (co)fixpoints.
+- Command "Search" has been renamed into "SearchHead". The command
+ name "Search" now behaves like former "SearchAbout". The latter name
+ is deprecated.
+- "Search", "About", "SearchHead", "SearchRewrite" and "SearchPattern"
+ now search for hypothesis (of the current goal by default) first.
+ They now also support the goal selector prefix to specify another
+ goal to search: e.g. "n:Search id". This is also true for
+ SearchAbout although it is deprecated.
+- The coq/user-contrib directory and the XDG directories are no longer
+ recursively added to the load path, so files from installed libraries
+ now need to be fully qualified for the "Require" command to find them.
+ The tools/update-require script can be used to convert a development.
+- A new Print Strategies command allows visualizing the opacity status
+ of the whole engine.
+- The "Locate" command now searches through all sorts of qualified namespaces of
+ Coq: terms, modules, tactics, etc. The old behavior of the command can be
+ retrieved using the "Locate Term" command.
+- New "Derive" command to help writing program by derivation.
+- New "Refine Instance Mode" option that allows to deactivate the generation of
+ obligations in incomplete typeclass instances, raising an error instead.
+- "Collection" command to name sets of section hypotheses. Named collections
+ can be used in the syntax of "Proof using" to assert which section variables
+ are used in a proof.
+- The "Optimize Proof" command can be placed in the middle of a proof to
+ force the compaction of the data structure used to represent the ongoing
+ proof (evar map). This may result in a lower memory footprint and speed up
+ the execution of the following tactics.
+- "Optimize Heap" command to tell the OCaml runtime to perform a major
+ garbage collection step and heap compaction.
+- "Instance" no longer treats the {|...|} syntax specially; it handles it
+ in the same way as other commands, e.g. "Definition". Use the {...}
+ syntax (no pipe symbols) to recover the old behavior.
+
+Specification Language
+
+- Slight changes in unification error messages.
+- Added a syntax $(...)$ that allows putting tactics in terms (may
+ break user notations using "$(", fixable by inserting a space or
+ rewriting the notation).
+- Constructors in pattern-matching patterns now respect the same rules
+ regarding implicit arguments as in applicative position. The old
+ behavior can be recovered by the command "Set Asymmetric
+ Patterns". As a side effect, notations for constructors explicitly
+ mentioning non-implicit parameters can now be used in patterns.
+ Considering that the pattern language is already rich enough, binding
+ local definitions is however now forbidden in patterns (source of
+ incompatibilities for local definitions that delta-reduce to a constructor).
+- Type inference algorithm now granting opacity of constants. This might also
+ affect behavior of tactics (source of incompatibilities, solvable by
+ re-declaring transparent constants which were set opaque).
+- Existential variables are now referred to by an identifier and the
+ relevant part of their instance is displayed by default. They can be
+ reparsed. The naming policy is yet unstable and subject to changes
+ in future releases.
+
+Tactics
+
+- New tactic engine allowing dependent subgoals, fully backtracking
+ (also known as multiple success) tactics, as well as tactics which
+ can consider multiple goals together. In the new tactic engine,
+ instantiation information of existential variables is always
+ propagated to tactics, removing the need to manually use the
+ "instantiate" tactics to mark propagation points.
+ * New tactical (a+b) inserts a backtracking point. When (a+b);c fails
+ during the execution of c, it can backtrack and try b instead of a.
+ * New tactical (once a) removes all the backtracking points from a
+ (i.e. it selects the first success of a).
+ * Tactic "constructor" is now fully backtracking. In case of
+ incompatibilities (e.g. combinatoric explosion), the former
+ behavior of "constructor" can be retrieved by using instead
+ "[> once constructor ..]". Thanks to backtracking, undocumented
+ "constructor <tac>" syntax is now equivalent to
+ "[> once (constructor; tac) ..]".
+ * New "multimatch" variant of "match" tactic which backtracks to
+ new branches in case of a later failure. The "match" tactic is
+ equivalent to "once multimatch".
+ * New selector "all:" such that "all:tac" applies tactic "tac" to
+ all the focused goals, instead of just the first one as is the
+ default.
+ * A corresponding new option Set Default Goal Selector "all" makes
+ the tactics in scripts be applied to all the focused goal by default
+ * New selector "par:" such that "par:tac" applies the (terminating)
+ tactic "tac" to all the focused goal in parallel. The number of worker
+ can be selected with -async-proofs-tac-j and also limited using the
+ coqworkmgr utility.
+ * New tactics "revgoals", "cycle" and "swap" to reorder goals.
+ * The semantics of recursive tactics (introduced with "Ltac t := ..."
+ or "let rec t := ... in ...") changed slightly as t is now
+ applied to every goal, not each goal independently. In particular
+ it may be applied when no goals are left. This may cause tactics
+ such as "let rec t := constructor;t" to loop indefinitely. The
+ simple fix is to rewrite the recursive calls as follows:
+ "let rec t := constructor;[t..]" which recovers the earlier behavior
+ (source of rare incompatibilities).
+ * New tactic language feature "numgoals" to count number of goals. It is
+ accompanied by a "guard" tactic which fails if a Boolean test over
+ integers does not pass.
+ * New tactical "[> ... ]" to apply tactics to individual goals.
+ * New tactic "gfail" which works like "fail" except it will also
+ fail if every goal has been solved.
+ * The refine tactic is changed not to use an ad hoc typing algorithm
+ to generate subgoals. It also uses the dependent subgoal feature
+ to generate goals to materialize every existential variable which
+ is introduced by the refinement (source of incompatibilities).
+ * A tactic shelve is introduced to manage the subgoals which may be
+ solved by unification: shelve removes every goal it is applied to
+ from focus. These goals can later be called back into focus by the
+ Unshelve command.
+ * A variant shelve_unifiable only removes those goals which appear
+ as existential variables in other goals. To emulate the old
+ refine, use "refine c;shelve_unifiable". This can still cause
+ incompatibilities in rare occasions.
+ * New "give_up" tactic to skip over a goal. A proof containing
+ given up goals cannot be closed with "Qed", but only with "Admitted".
+- The implementation of the admit tactic has changed: no axiom is
+ generated for the admitted sub proof. "admit" is now an alias for
+ "give_up". Code relying on this specific behavior of "admit"
+ can be made to work by:
+ * Adding an "Axiom" for each admitted subproof.
+ * Adding a single "Axiom proof_admitted : False." and the Ltac definition
+ "Ltac admit := case proof_admitted.".
+- Matching using "lazymatch" was fundamentally modified. It now behaves
+ like "match" (immediate execution of the matching branch) but without
+ the backtracking mechanism in case of failure.
+- New "tryif t then u else v" tactical which executes "u" in case of success
+ of "t" and "v" in case of failure.
+- New conversion tactic "native_compute": evaluates the goal (or an hypothesis)
+ with a call-by-value strategy, using the OCaml native compiler. Useful on
+ very intensive computations.
+- New "cbn" tactic, a well-behaved simpl.
+- Repeated identical calls to omega should now produce identical proof terms.
+- Tactics btauto, a reflexive Boolean tautology solver.
+- Tactic "tauto" was exceptionally able to destruct other connectives
+ than the binary connectives "and", "or", "prod", "sum", "iff". This
+ non-uniform behavior has been fixed (bug #2680) and tauto is
+ slightly weaker (possible source of incompatibilities). On the
+ opposite side, new tactic "dtauto" is able to destruct any
+ record-like inductive types, superseding the old version of "tauto".
+- Similarly, "intuition" has been made more uniform and, where it now
+ fails, "dintuition" can be used (possible source of incompatibilities).
+- New option "Unset Intuition Negation Unfolding" for deactivating automatic
+ unfolding of "not" in intuition.
+- Tactic notations can now be defined locally to a module (use "Local" prefix).
+- Tactic "red" now reduces head beta-iota redexes (potential source of
+ rare incompatibilities).
+- Tactic "hnf" now reduces inner beta-iota redexes
+ (potential source of rare incompatibilities).
+- Tactic "intro H" now reduces beta-iota redexes if these hide a product
+ (potential source of rare incompatibilities).
+- In Ltac matching on patterns of the form "_ pat1 ... patn" now
+ behaves like if matching on "?X pat1 ... patn", i.e. accepting "_"
+ to be instantiated by an applicative term (experimental at this
+ stage, potential source of incompatibilities).
+- In Ltac matching on goal, types of hypotheses are now interpreted in
+ the %type scope (possible source of incompatibilities).
+- "change ... in ..." and "simpl ... in ..." now properly consider nested
+ occurrences (possible source of incompatibilities since this alters
+ the numbering of occurrences), but do not support nested occurrences.
+- Tactics simpl, vm_compute and native_compute can be given a notation string
+ to a constant as argument.
+- When given a reference as argument, simpl, vm_compute and
+ native_compute now strictly interpret it as the head of a pattern
+ starting with this reference.
+- The "change p with c" tactic semantics changed, now type-checking
+ "c" at each matching occurrence "t" of the pattern "p", and
+ converting "t" with "c".
+- Now "appcontext" and "context" behave the same. The old buggy behavior of
+ "context" can be retrieved at parse time by setting the
+ "Tactic Compat Context" flag (possible source of incompatibilities).
+- New introduction pattern p/c which applies lemma c on the fly on the
+ hypothesis under consideration before continuing with introduction pattern p.
+- New introduction pattern [= x1 .. xn] applies "injection as [x1 .. xn]"
+ on the fly if injection is applicable to the hypothesis under consideration
+ (idea borrowed from Georges Gonthier). Introduction pattern [=] applies
+ "discriminate" if a discriminable equality.
+- New introduction patterns * and ** to respectively introduce all forthcoming
+ dependent variables and all variables/hypotheses dependent or not.
+- Tactic "injection c as ipats" now clears c if c refers to an
+ hypothesis and moves the resulting equations in the hypotheses
+ independently of the number of ipats, which has itself to be less
+ than the number of new hypotheses (possible source of incompatibilities;
+ former behavior obtainable by "Unset Injection L2R Pattern Order").
+- Tactic "injection" now automatically simplifies subgoals
+ "existT n p = existT n p'" into "p = p'" when "n" is in an inductive type for
+ which a decidable equality scheme has been generated with "Scheme Equality"
+ (possible source of incompatibilities).
+- New tactic "rewrite_strat" for generalized rewriting with user-defined
+ strategies, subsuming autorewrite.
+- Injection can now also deduce equality of arguments of sort Prop, by using
+ the option "Set Injection On Proofs" (disabled by default). Also improved the
+ error messages.
+- Tactic "subst id" now supports id occurring in dependent local definitions.
+- Bugs fixed about intro-pattern "*" might lead to some rare incompatibilities.
+- New tactical "time" to display time spent executing its argument.
+- Tactics referring or using a constant dependent in a section variable which
+ has been cleared or renamed in the current goal context now fail
+ (possible source of incompatibilities solvable by avoiding clearing
+ the relevant hypotheses).
+- New construct "uconstr:c" and "type_term c" to build untyped terms.
+- Binders in terms defined in Ltac (either "constr" or "uconstr") can
+ now take their names from identifiers defined in Ltac. As a
+ consequence, a name cannot be used in a binder "constr:(fun x =>
+ ...)" if an Ltac variable of that name already exists and does not
+ contain an identifier. Source of occasional incompatibilities.
+- The "refine" tactic now accepts untyped terms built with "uconstr"
+ so that terms with holes can be constructed piecewise in Ltac.
+- New bullets --, ++, **, ---, +++, ***, ... made available.
+- More informative messages when wrong bullet is used.
+- Bullet suggestion when a subgoal is solved.
+- New tactic "enough", symmetric to "assert", but with subgoals
+ swapped, as a more friendly replacement of "cut".
+- In destruct/induction, experimental modifier "!" prefixing the
+ hypothesis name to tell not erasing the hypothesis.
+- Bug fixes in "inversion as" may occasionally lead to incompatibilities.
+- Behavior of introduction patterns -> and <- made more uniform
+ (hypothesis is cleared, rewrite in hypotheses and conclusion and
+ erasing the variable when rewriting a variable).
+- New experimental option "Set Standard Proposition Elimination Names"
+ so that case analysis or induction on schemes in Type containing
+ propositions now produces "H"-based names.
+- Tactics from plugins are now active only when the corresponding module
+ is imported (source of incompatibilities, solvable by adding an "Import";
+ in the particular case of Omega, use "Require Import OmegaTactic").
+- Semantics of destruct/induction has been made more regular in some
+ edge cases, possibly leading to incompatibilities:
+ - new goals are now opened when the term does not match a subterm of
+ the goal and has unresolved holes, while in 8.4 these holes were
+ turned into existential variables
+ - when no "at" option is given, the historical semantics which
+ selects all subterms syntactically identical to the first subterm
+ matching the given pattern is used
+ - non-dependent destruct/induction on an hypothesis with premises in
+ an inductive type with indices is fixed
+ - residual local definitions are now correctly removed.
+- The rename tactic may now replace variables in parallel.
+- A new "Info" command replaces the "info" tactical discontinued in
+ v8.4. It still gives informative results in many cases.
+- The "info_auto" tactic is known to be broken and does not print a
+ trace anymore. Use "Info 1 auto" instead. The same goes for
+ "info_trivial". On the other hand "info_eauto" still works fine,
+ while "Info 1 eauto" prints a trivial trace.
+- When using a lemma of the prototypical form "forall A, {a:A & P a}",
+ "apply" and "apply in" do not instantiate anymore "A" with the
+ current goal and use "a" as the proof, as they were sometimes doing,
+ now considering that it is a too powerful decision.
+
+Program
+
+- "Solve Obligations using" changed to "Solve Obligations with",
+ consistent with "Proof with".
+- Program Lemma, Definition now respect automatic introduction.
+- Program Lemma, Definition, etc.. now interpret "->" like Lemma and
+ Definition as a non-dependent arrow (potential source of
+ incompatibility).
+- Add/document "Set Hide Obligations" (to hide obligations in the final
+ term inside an implicit argument) and "Set Shrink Obligations" (to
+ minimize dependencies of obligations defined by tactics).
+
+Notations
+
+- The syntax "x -> y" is now declared at level 99. In particular, it has
+ now a lower priority than "<->": "A -> B <-> C" is now "A -> (B <-> C)"
+ (possible source of incompatibilities)
+- Notations accept term-providing tactics using the $(...)$ syntax.
+- "Bind Scope" can no longer bind "Funclass" and "Sortclass".
+- A notation can be given a (compat "8.x") annotation, making it behave
+ like a "only parsing" notation, but the annotation may lead to eventually
+ issue warnings or errors in further versions when this notation is used.
+- More systematic insertion of spaces as a default for printing
+ notations ("format" still available to override the default).
+- In notations, a level modifier referring to a non-existent variable is
+ now considered an error rather than silently ignored.
+
+Tools
+
+- Option -I now only adds directories to the ml path.
+- Option -Q behaves as -R, except that the logical path of any loaded file has
+ to be fully qualified.
+- Option -R no longer adds recursively to the ml path; only the root
+ directory is added. (Behavior with respect to the load path is
+ unchanged.)
+- Option -nois prevents coq/theories and coq/plugins to be recursively
+ added to the load path. (Same behavior as with coq/user-contrib.)
+- coqdep accepts a -dumpgraph option generating a dot file.
+- Makefiles generated through coq_makefile have three new targets "quick"
+ "checkproofs" and "vio2vo", allowing respectively to asynchronously compile
+ the files without playing the proof scripts, asynchronously checking
+ that the quickly generated proofs are correct and generating the object
+ files from the quickly generated proofs.
+- The XML plugin was discontinued and removed from the source.
+- A new utility called coqworkmgr can be used to limit the number of
+ concurrent workers started by independent processes, like make and CoqIDE.
+ This is of interest for users of the par: goal selector.
+
+Interfaces
+
+- CoqIDE supports asynchronous edition of the document, ongoing tasks and
+ errors are reported in the bottom right window. The number of workers
+ taking care of processing proofs can be selected with -async-proofs-j.
+- CoqIDE highlights in yellow "unsafe" commands such as axiom
+ declarations, and tactics like "give_up".
+- CoqIDE supports Proof General like key bindings;
+ to activate the PG mode go to Edit -> Preferences -> Editor.
+ For the documentation see Help -> Help for PG mode.
+- CoqIDE automatically retracts the locked area when one edits the
+ locked text.
+- CoqIDE search and replace got regular expressions power. See the
+ documentation of OCaml's Str module for the supported syntax.
+- Many CoqIDE windows, including the query one, are now detachable to
+ improve usability on multi screen work stations.
+- Coqtop/coqc outputs highlighted syntax. Colors can be configured thanks
+ to the COQ_COLORS environment variable, and their current state can
+ be displayed with the -list-tags command line option.
+- Third party user interfaces can install their main loop in $COQLIB/toploop
+ and call coqtop with the -toploop flag to select it.
+
+Internal Infrastructure
+
+- Many reorganizations in the ocaml source files. For instance,
+ many internal a.s.t. of Coq are now placed in mli files in
+ a new directory intf/, for instance constrexpr.mli or glob_term.mli.
+ More details in dev/doc/changes.
+- The file states/initial.coq does not exist anymore. Instead, coqtop
+ initially does a "Require" of Prelude.vo (or nothing when given
+ the options -noinit or -nois).
+- The format of vo files has slightly changed: cf final comments in
+ checker/cic.mli.
+- The build system does not produce anymore programs named coqtop.opt
+ and a symbolic link to coqtop. Instead, coqtop is now directly
+ an executable compiled with the best OCaml compiler available.
+ The bytecode program coqtop.byte is still produced. Same for other
+ utilities.
+- Some options of the ./configure script slightly changed:
+ * The -coqrunbyteflags and its blank-separated argument is replaced
+ by option -vmbyteflags which expects a comma-separated argument.
+ * The -coqtoolsbyteflags option is discontinued, see -no-custom instead.
+
+Miscellaneous
+
+- ML plugins now require a "DECLARE PLUGIN \"foo\"" statement. The "foo" name
+ must be exactly the name of the ML module that will be loaded through a
+ "Declare ML \"foo\"" command.
+
+Changes from V8.4beta2 to V8.4
+==============================
+
+Vernacular commands
+
+- The "Reset" command is now supported again in files given to coqc or Load.
+- "Show Script" now indents again the displayed scripts. It can also work
+ correctly across Load'ed files if the option "Unset Atomic Load" is used.
+- "Open Scope" can now be given the delimiter (e.g. Z) instead of the full
+ scope name (e.g. Z_scope).
+
+Notations
+
+- Most compatibility notations of the standard library are now tagged as
+ (compat xyz), where xyz is a former Coq version, for instance "8.3".
+ These notations behave as (only parsing) notations, except that they may
+ triggers warnings (or errors) when used while Coq is not in a corresponding
+ -compat mode.
+- To activate these compatibility warnings, use "Set Verbose Compat Notations"
+ or the command-line flag -verbose-compat-notations.
+- For a strict mode without these compatibility notations, use
+ "Unset Compat Notations" or the command-line flag -no-compat-notations.
+
+Tactics
+
+- An annotation "eqn:H" or "eqn:?" can be added to a "destruct"
+ or "induction" to make it generate equations in the spirit of "case_eq".
+ The former syntax "_eqn" is discontinued.
+- The name of the hypothesis introduced by tactic "remember" can be
+ set via the new syntax "remember t as x eqn:H" (wish #2489).
+
+Libraries
+
+- Reals: changed definition of PI, no more axiom about sin(PI/2).
+- SetoidPermutation: a notion of permutation for lists modulo a setoid equality.
+- BigN: fixed the ocaml code doing the parsing/printing of big numbers.
+- List: a couple of lemmas added especially about no-duplication, partitions.
+- Init: Removal of the coercions between variants of sigma-types and
+ subset types (possible source of incompatibility).
+
+Changes from V8.4beta to V8.4beta2
+==================================
+
+Vernacular commands
+
+- Commands "Back" and "BackTo" are now handling the proof states. They may
+ perform some extra steps of backtrack to avoid states where the proof
+ state is unavailable (typically a closed proof).
+- The commands "Suspend" and "Resume" have been removed.
+- A basic Show Script has been reintroduced (no indentation).
+- New command "Set Parsing Explicit" for deactivating parsing (and printing)
+ of implicit arguments (useful for teaching).
+- New command "Grab Existential Variables" to transform the unresolved evars
+ at the end of a proof into goals.
+
+Tactics
+
+- Still no general "info" tactical, but new specific tactics info_auto,
+ info_eauto, info_trivial which provides information on the proofs found
+ by auto/eauto/trivial. Display of these details could also be activated by
+ "Set Info Auto"/"Set Info Eauto"/"Set Info Trivial".
+- Details on everything tried by auto/eauto/trivial during a proof search
+ could be obtained by "debug auto", "debug eauto", "debug trivial" or by a
+ global "Set Debug Auto"/"Set Debug Eauto"/"Set Debug Trivial".
+- New command "r string" in Ltac debugger that interprets "idtac
+ string" in Ltac code as a breakpoint and jumps to its next use.
+- Tactics from the Dp plugin (simplify, ergo, yices, cvc3, z3, cvcl,
+ harvey, zenon, gwhy) have been removed, since Why2 has not been
+ maintained for the last few years. The Why3 plugin should be a suitable
+ replacement in most cases.
+
+Libraries
+
+- MSetRBT: a new implementation of MSets via Red-Black trees (initial
+ contribution by Andrew Appel).
+- MSetAVL: for maximal sharing with the new MSetRBT, the argument order
+ of Node has changed (this should be transparent to regular MSets users).
+
+Module System
+
+- The names of modules (and module types) are now in a fully separated
+ namespace from ordinary definitions: "Definition E:=0. Module E. End E."
+ is now accepted.
+
+CoqIDE
+
+- Coqide now supports the "Restart" command, and "Undo" (with a warning).
+ Better support for "Abort".
+
+Changes from V8.3 to V8.4beta
+=============================
+
+Logic
+
+- Standard eta-conversion now supported (dependent product only).
+- Guard condition improvement: subterm property is propagated through beta-redex
+ blocked by pattern-matching, as in "(match v with C .. => fun x => u end) x";
+ this allows for instance to use "rewrite ... in ..." without breaking
+ the guard condition.
+
+Specification language and notations
+
+- Maximal implicit arguments can now be set locally by { }. The registration
+ traverses fixpoints and lambdas. Because there is conversion in types,
+ maximal implicit arguments are not taken into account in partial
+ applications (use eta expanded form with explicit { } instead).
+- Added support for recursive notations with binders (allows for instance
+ to write "exists x y z, P").
+- Structure/Record printing can be disable by "Unset Printing Records".
+ In addition, it can be controlled on type by type basis using
+ "Add Printing Record" or "Add Printing Constructor".
+- Pattern-matching compilation algorithm: in "match x, y with ... end",
+ possible dependencies of x (or of the indices of its type) in the type
+ of y are now taken into account.
+
+Tactics
+
+- New proof engine.
+- Scripts can now be structured thanks to bullets - * + and to subgoal
+ delimitation via { }. Note: for use with Proof General, a cvs version of
+ Proof General no older than mid-July 2011 is currently required.
+- Support for tactical "info" is suspended.
+- Support for command "Show Script" is suspended.
+- New tactics constr_eq, is_evar and has_evar for use in Ltac (DOC TODO).
+- Removed the two-argument variant of "decide equality".
+- New experimental tactical "timeout <n> <tac>". Since <n> is a time
+ in second for the moment, this feature should rather be avoided
+ in scripts meant to be machine-independent.
+- Fix in "destruct": removal of unexpected local definitions in context might
+ result in some rare incompatibilities (solvable by adapting name hypotheses).
+- Introduction pattern "_" made more robust.
+- Tactic (and Eval command) vm_compute can now be interrupted via Ctrl-C.
+- Unification in "apply" supports unification of patterns of the form
+ ?f x y = g(x,y) (compatibility ensured by using
+ "Unset Tactic Pattern Unification"). It also supports (full) betaiota.
+- Tactic autorewrite does no longer instantiate pre-existing
+ existential variables (theoretical source of possible incompatibilities).
+- Tactic "dependent rewrite" now supports equality in "sig".
+- Tactic omega now understands Zpred (wish #1912) and can prove any goal
+ from a context containing an arithmetical contradiction (wish #2236).
+- Using "auto with nocore" disables the use of the "core" database (wish #2188).
+ This pseudo-database "nocore" can also be used with trivial and eauto.
+- Tactics "set", "destruct" and "induction" accepts incomplete terms and
+ use the goal to complete the pattern assuming it is non ambiguous.
+- When used on arguments with a dependent type, tactics such as
+ "destruct", "induction", "case", "elim", etc. now try to abstract
+ automatically the dependencies over the arguments of the types
+ (based on initial ideas from Chung-Kil Hur, extension to nested
+ dependencies suggested by Dan Grayson)
+- Tactic "injection" now failing on an equality showing no constructors while
+ it was formerly generalizing again the goal over the given equality.
+- In Ltac, the "context [...]" syntax has now a variant "appcontext [...]"
+ allowing to match partial applications in larger applications.
+- When applying destruct or inversion on a fixpoint hiding an inductive
+ type, recursive calls to the fixpoint now remain folded by default (rare
+ source of incompatibility generally solvable by adding a call to simpl).
+- In an ltac pattern containing a "match", a final "| _ => _" branch could be
+ used now instead of enumerating all remaining constructors. Moreover, the
+ pattern "match _ with _ => _ end" now allows to match any "match". A "in"
+ annotation can also be added to restrict to a precise inductive type.
+- The behavior of "simpl" can be tuned using the "Arguments" vernacular.
+ In particular constants can be marked so that they are always/never unfolded
+ by "simpl", or unfolded only when a set of arguments evaluates to a
+ constructor. Last one can mark a constant so that it is unfolded only if the
+ simplified term does not expose a match in head position.
+
+Vernacular commands
+
+- It is now mandatory to have a space (or tabulation or newline or end-of-file)
+ after a "." ending a sentence.
+- In SearchAbout, the [ ] delimiters are now optional.
+- New command "Add/Remove Search Blacklist <substring> ...":
+ a Search or SearchAbout or similar query will never mention lemmas
+ whose qualified names contain any of the declared substrings.
+ The default blacklisted substrings are "_subproof" "Private_".
+- When the output file of "Print Universes" ends in ".dot" or ".gv",
+ the universe graph is printed in the DOT language, and can be
+ processed by Graphviz tools.
+- New command "Print Sorted Universes".
+- The undocumented and obsolete option "Set/Unset Boxed Definitions" has
+ been removed, as well as syntaxes like "Boxed Fixpoint foo".
+- A new option "Set Default Timeout n / Unset Default Timeout".
+- Qed now uses information from the reduction tactics used in proof script
+ to avoid conversion at Qed time to go into a very long computation.
+- New command "Show Goal ident" to display the statement of a goal, even
+ a closed one (available from Proof General).
+- Command "Proof" accept a new modifier "using" to force generalization
+ over a given list of section variables at section ending (DOC TODO).
+- New command "Arguments" generalizing "Implicit Arguments" and
+ "Arguments Scope" and that also allows to rename the parameters of a
+ definition and to tune the behavior of the tactic "simpl".
+
+Module System
+
+- During subtyping checks, an opaque constant in a module type could now
+ be implemented by anything of the right type, even if bodies differ.
+ Said otherwise, with respect to subtyping, an opaque constant behaves
+ just as a parameter. Coqchk was already implementing this, but not coqtop.
+- The inlining done during application of functors can now be controlled
+ more precisely, by the annotations (no inline) or (inline at level XX).
+ With the latter annotation, only functor parameters whose levels
+ are lower or equal than XX will be inlined.
+ The level of a parameter can be fixed by "Parameter Inline(30) foo".
+ When levels aren't given, the default value is 100. One can also use
+ the flag "Set Inline Level ..." to set a level (DOC TODO).
+- Print Assumptions should now handle correctly opaque modules (#2168).
+- Print Module (Type) now tries to print more details, such as types and
+ bodies of the module elements. Note that Print Module Type could be
+ used on a module to display only its interface. The option
+ "Set Short Module Printing" could be used to switch back to the earlier
+ behavior were only field names were displayed.
+
+Libraries
+
+- Extension of the abstract part of Numbers, which now provide axiomatizations
+ and results about many more integer functions, such as pow, gcd, lcm, sqrt,
+ log2 and bitwise functions. These functions are implemented for nat, N, BigN,
+ Z, BigZ. See in particular file NPeano for new functions about nat.
+- The definition of types positive, N, Z is now in file BinNums.v
+- Major reorganization of ZArith. The initial file ZArith/BinInt.v now contains
+ an internal module Z implementing the Numbers interface for integers.
+ This module Z regroups:
+ * all functions over type Z : Z.add, Z.mul, ...
+ * the minimal proofs of specifications for these functions : Z.add_0_l, ...
+ * an instantation of all derived properties proved generically in Numbers :
+ Z.add_comm, Z.add_assoc, ...
+ A large part of ZArith is now simply compatibility notations, for instance
+ Zplus_comm is an alias for Z.add_comm. The direct use of module Z is now
+ recommended instead of relying on these compatibility notations.
+- Similar major reorganization of NArith, via a module N in NArith/BinNat.v
+- Concerning the positive datatype, BinPos.v is now in a specific directory
+ PArith, and contains an internal submodule Pos. We regroup there functions
+ such as Pos.add Pos.mul etc as well as many results about them. These results
+ are here proved directly (no Number interface for strictly positive numbers).
+- Note that in spite of the compatibility layers, all these reorganizations
+ may induce some marginal incompatibilies in scripts. In particular:
+ * the "?=" notation for positive now refers to a binary function Pos.compare,
+ instead of the infamous ternary Pcompare (now Pos.compare_cont).
+ * some hypothesis names generated by the system may changed (typically for
+ a "destruct Z_le_gt_dec") since naming is done after the short name of
+ the head predicate (here now "le" in module Z instead of "Zle", etc).
+ * the internals of Z.add has changed, now relying of Z.pos_sub.
+- Also note these new notations:
+ * "<?" "<=?" "=?" for boolean tests such as Z.ltb Z.leb Z.eqb.
+ * "÷" for the alternative integer division Z.quot implementing the Truncate
+ convention (former ZOdiv), while the notation for the Coq usual division
+ Z.div implementing the Flooring convention remains "/". Their corresponding
+ modulo functions are Z.rem (no notations) for Z.quot and Z.modulo (infix
+ "mod" notation) for Z.div.
+- Lemmas about conversions between these datatypes are also organized
+ in modules, see for instance modules Z2Nat, N2Z, etc.
+- When creating BigN, the macro-generated part NMake_gen is much smaller.
+ The generic part NMake has been reworked and improved. Some changes
+ may introduce incompatibilities. In particular, the order of the arguments
+ for BigN.shiftl and BigN.shiftr is now reversed: the number to shift now
+ comes first. By default, the power function now takes two BigN.
+- Creation of Vector, an independent library for lists indexed by their length.
+ Vectors' names overwrite lists' one so you should not "Import" the library.
+ All old names changed: function names follow the ocaml ones and, for example,
+ Vcons becomes Vector.cons. You can get [..;..;..]-style notations by importing
+ Vector.VectorNotations.
+- Removal of TheoryList. Requiring List instead should work most of the time.
+- New syntax "rew Heq in H" and "rew <- Heq in H" for eq_rect and
+ eq_rect_r (available by importing module EqNotations).
+- Wf.iter_nat is now Peano.nat_iter (with an implicit type argument).
+
+Internal infrastructure
+
+- Opaque proofs are now loaded lazily by default. This allows to be almost as
+ fast as -dont-load-proofs, while being safer (no creation of axioms) and
+ avoiding feature restrictions (Print and Print Assumptions work ok).
+- Revised hash-consing code allowing more sharing of memory
+- Experimental support added for camlp4 (the one provided alongside ocaml),
+ simply pass option -usecamlp4 to ./configure. By default camlp5 is used.
+- Revised build system: no more stages in Makefile thanks to some recursive
+ aspect of recent gnu make, use of vo.itarget files containing .v to compile
+ for both make and ocamlbuild, etc.
+- Support of cross-compilation via mingw from unix toward Windows,
+ contact P. Letouzey for more informations.
+- New Makefile rules mli-doc to make html of mli in dev/doc/html and
+ full-stdlib to get a (huge) pdf reflecting the whole standard library.
+
+Extraction
+
+- By default, opaque terms are now truly considered opaque by extraction:
+ instead of accessing their body, they are now considered as axioms.
+ The previous behaviour can be reactivated via the option
+ "Set Extraction AccessOpaque".
+- The pretty-printer for Haskell now produces layout-independent code
+- A new command "Separate Extraction cst1 cst2 ..." that mixes a
+ minimal extracted environment a la "Recursive Extraction" and the
+ production of several files (one per coq source) a la "Extraction Library"
+ (DOC TODO).
+- New option "Set/Unset Extraction KeepSingleton" for preventing the
+ extraction to optimize singleton container types (DOC TODO).
+- The extraction now identifies and properly rejects a particular case of
+ universe polymorphism it cannot handle yet (the pair (I,I) being Prop).
+- Support of anonymous fields in record (#2555).
+
+CoqIDE
+
+- Coqide now runs coqtop as separated process, making it more robust:
+ coqtop subprocess can be interrupted, or even killed and relaunched
+ (cf button "Restart Coq", ex-"Go to Start"). For allowing such
+ interrupts, the Windows version of coqide now requires Windows >= XP
+ SP1.
+- The communication between CoqIDE and Coqtop is now done via a dialect
+ of XML (DOC TODO).
+- The backtrack engine of CoqIDE has been reworked, it now uses the
+ "Backtrack" command similarly to Proof General.
+- The Coqide parsing of sentences has be reworked and now supports
+ tactic delimitation via { }.
+- Coqide now accepts the Abort command (wish #2357).
+- Coqide can read coq_makefile files as "project file" and use it to
+ set automatically options to send to coqtop.
+- Preference files have moved to $XDG_CONFIG_HOME/coq and accelerators
+ are not stored as a list anymore.
+
+Tools
+
+- Coq now searches directories specified in COQPATH, $XDG_DATA_HOME/coq,
+ $XDG_DATA_DIRS/coq, and user-contribs before the standard library.
+- Coq rc file has moved to $XDG_CONFIG_HOME/coq.
+- Major changes to coq_makefile:
+ * mli/mlpack/mllib taken into account, ml not preproccessed anymore, ml4 work;
+ * mlihtml generates doc of mli, install-doc install the html doc in DOCDIR
+ with the same policy as vo in COQLIB;
+ * More variables are given by coqtop -config, others are defined only if the
+ users doesn't have defined them elsewhere. Consequently, generated makefile
+ should work directly on any architecture;
+ * Packagers can take advantage of $(DSTROOT) introduction. Installation can
+ be made in $XDG_DATA_HOME/coq;
+ * -arg option allows to send option as argument to coqc.
+
+Changes from V8.2 to V8.3
+=========================
+
+Rewriting tactics
+
+- Tactic "rewrite" now supports rewriting on ad hoc equalities such as eq_true.
+- "Hint Rewrite" now checks that the lemma looks like an equation.
+- New tactic "etransitivity".
+- Support for heterogeneous equality (JMeq) in "injection" and "discriminate".
+- Tactic "subst" now supports heterogeneous equality and equality
+ proofs that are dependent (use "simple subst" for preserving compatibility).
+- Added support for Leibniz-rewriting of dependent hypotheses.
+- Renamed "Morphism" into "Proper" and "respect" into "proper_prf"
+ (possible source of incompatibility). A partial fix is to define
+ "Notation Morphism R f := (Proper (R%signature) f)."
+- New tactic variants "rewrite* by" and "autorewrite*" that rewrite
+ respectively the first and all matches whose side-conditions are
+ solved.
+- "Require Import Setoid" does not export all of "Morphisms" and
+ "RelationClasses" anymore (possible source of incompatibility, fixed
+ by importing "Morphisms" too).
+- Support added for using Chung-Kil Hur's Heq library for rewriting over
+ heterogeneous equality (courtesy of the library's author).
+- Tactic "replace" supports matching terms with holes.
+
+Automation tactics
+
+- Tactic "intuition" now preserves inner "iff" and "not" (exceptional
+ source of incompatibilities solvable by redefining "intuition" as
+ "unfold iff, not in *; intuition", or, for iff only, by using
+ "Set Intuition Iff Unfolding".)
+- Tactic "tauto" now proves classical tautologies as soon as classical logic
+ (i.e. library Classical_Prop or Classical) is loaded.
+- Tactic "gappa" has been removed from the Dp plugin.
+- Tactic "firstorder" now supports the combination of its "using" and
+ "with" options.
+- New "Hint Resolve ->" (or "<-") for declaring iff's as oriented
+ hints (wish #2104).
+- An inductive type as argument of the "using" option of "auto/eauto/firstorder"
+ is interpreted as using the collection of its constructors.
+- New decision tactic "nsatz" to prove polynomial equations
+ by computation of Groebner bases.
+
+Other tactics
+
+- Tactic "discriminate" now performs intros before trying to discriminate an
+ hypothesis of the goal (previously it applied intro only if the goal
+ had the form t1<>t2) (exceptional source of incompatibilities - former
+ behavior can be obtained by "Unset Discriminate Introduction").
+- Tactic "quote" now supports quotation of arbitrary terms (not just the
+ goal).
+- Tactic "idtac" now displays its "list" arguments.
+- New introduction patterns "*" for introducing the next block of dependent
+ variables and "**" for introducing all quantified variables and hypotheses.
+- Pattern Unification for existential variables activated in tactics and
+ new option "Unset Tactic Evars Pattern Unification" to deactivate it.
+- Resolution of canonical structure is now part of the tactic's unification
+ algorithm.
+- New tactic "decide lemma with hyp" for rewriting decidability lemmas
+ when one knows which side is true.
+- Improved support of dependent goals over objects in dependent types for
+ "destruct" (rare source of incompatibility that can be avoided by unsetting
+ option "Dependent Propositions Elimination").
+- Tactic "exists", "eexists", "destruct" and "edestruct" supports iteration
+ using comma-separated arguments.
+- Tactic names "case" and "elim" now support clauses "as" and "in" and become
+ then synonymous of "destruct" and "induction" respectively.
+- A new tactic name "exfalso" for the use of 'ex-falso quodlibet' principle.
+ This tactic is simply a shortcut for "elimtype False".
+- Made quantified hypotheses get the name they would have if introduced in
+ the context (possible but rare source of incompatibilities).
+- When applying a component of a conjunctive lemma, "apply in" (and
+ sequences of "apply in") now leave the side conditions of the lemmas
+ uniformly after the main goal (possible source of rare incompatibilities).
+- In "simpl c" and "change c with d", c can be a pattern.
+- Tactic "revert" now preserves let-in's making it the exact inverse of
+ "intro".
+- New tactics "clear dependent H" and "revert dependent H" that
+ clears (resp. reverts) H and all the hypotheses that depend on H.
+- Ltac's pattern-matching now supports matching metavariables that
+ depend on variables bound upwards in the pattern.
+
+Tactic definitions
+
+- Ltac definitions support Local option for non-export outside modules.
+- Support for parsing non-empty lists with separators in tactic notations.
+- New command "Locate Ltac" to get the full name of an Ltac definition.
+
+Notations
+
+- Record syntax "{|x=...; y=...|}" now works inside patterns too.
+- Abbreviations from non-imported module now invisible at printing time.
+- Abbreviations now use implicit arguments and arguments scopes for printing.
+- Abbreviations to pure names now strictly behave like the name they refer to
+ (make redirections of qualified names easier).
+- Abbreviations for applied constant now propagate the implicit arguments
+ and arguments scope of the underlying reference (possible source of
+ incompatibilities generally solvable by changing such abbreviations from
+ e.g. "Notation foo' := (foo x)" to "Notation foo' y := (foo x (y:=y))").
+- The "where" clause now supports multiple notations per defined object.
+- Recursive notations automatically expand one step on the left for better
+ factorization; recursion notations inner separators now ensured being tokens.
+- Added "Reserved Infix" as a specific shortcut of the corresponding
+ "Reserved Notation".
+- Open/Close Scope command supports Global option in sections.
+
+Specification language
+
+- New support for local binders in the syntax of Record/Structure fields.
+- Fixpoint/CoFixpoint now support building part or all of bodies using tactics.
+- Binders given before ":" in lemmas and in definitions built by tactics are
+ now automatically introduced (possible source of incompatibility that can
+ be resolved by invoking "Unset Automatic Introduction").
+- New support for multiple implicit arguments signatures per reference.
+
+Module system
+
+- Include Type is now deprecated since Include now accept both modules and
+ module types.
+- Declare ML Module supports Local option.
+- The sharing between non-logical object and the management of the
+ name-space has been improved by the new "Delta-equivalence" on
+ qualified name.
+- The include operator has been extended to high-order structures
+- Sequences of Include can be abbreviated via new syntax "<+".
+- A module (or module type) can be given several "<:" signatures.
+- Interactive proofs are now permitted in module type. Functors can hence
+ be declared as Module Type and be used later to type themselves.
+- A functor application can be prefixed by a "!" to make it ignore any
+ "Inline" annotation in the type of its argument(s) (for examples of
+ use of the new features, see libraries Structures and Numbers).
+- Coercions are now active only when modules are imported (use "Set Automatic
+ Coercions Import" to get the behavior of the previous versions of Coq).
+
+Extraction
+
+- When using (Recursive) Extraction Library, the filenames are directly the
+ Coq ones with new appropriate extensions : we do not force anymore
+ uncapital first letters for Ocaml and capital ones for Haskell.
+- The extraction now tries harder to avoid code transformations that can be
+ dangerous for the complexity. In particular many eta-expansions at the top
+ of functions body are now avoided, clever partial applications will likely
+ be preserved, let-ins are almost always kept, etc.
+- In the same spirit, auto-inlining is now disabled by default, except for
+ induction principles, since this feature was producing more frequently
+ weird code than clear gain. The previous behavior can be restored via
+ "Set Extraction AutoInline".
+- Unicode characters in identifiers are now transformed into ascii strings
+ that are legal in Ocaml and other languages.
+- Harsh support of module extraction to Haskell and Scheme: module hierarchy
+ is flattened, module abbreviations and functor applications are expanded,
+ module types and unapplied functors are discarded.
+- Less unsupported situations when extracting modules to Ocaml. In particular
+ module parameters might be alpha-renamed if a name clash is detected.
+- Extract Inductive is now possible toward non-inductive types (e.g. nat => int)
+- Extraction Implicit: this new experimental command allows to mark
+ some arguments of a function or constructor for removed during
+ extraction, even if these arguments don't fit the usual elimination
+ principles of extraction, for instance the length n of a vector.
+- Files ExtrOcaml*.v in plugins/extraction try to provide a library of common
+ extraction commands: mapping of basics types toward Ocaml's counterparts,
+ conversions from/to int and big_int, or even complete mapping of nat,Z,N
+ to int or big_int, or mapping of ascii to char and string to char list
+ (in this case recognition of ascii constants is hard-wired in the extraction).
+
+Program
+
+- Streamlined definitions using well-founded recursion and measures so
+ that they can work on any subset of the arguments directly (uses currying).
+- Try to automatically clear structural fixpoint prototypes in
+ obligations to avoid issues with opacity.
+- Use return type clause inference in pattern-matching as in the standard
+ typing algorithm.
+- Support [Local Obligation Tactic] and [Next Obligation with tactic].
+- Use [Show Obligation Tactic] to print the current default tactic.
+- [fst] and [snd] have maximal implicit arguments in Program now (possible
+ source of incompatibility).
+
+Type classes
+
+- Declaring axiomatic type class instances in Module Type should be now
+ done via new command "Declare Instance", while the syntax "Instance"
+ now always provides a concrete instance, both in and out of Module Type.
+- Use [Existing Class foo] to declare foo as a class a posteriori.
+ [foo] can be an inductive type or a constant definition. No
+ projections or instances are defined.
+- Various bug fixes and improvements: support for defined fields,
+ anonymous instances, declarations giving terms, better handling of
+ sections and [Context].
+
+Vernacular commands
+
+- New command "Timeout <n> <command>." interprets a command and a timeout
+ interrupts the interpretation after <n> seconds.
+- New command "Compute <expr>." is a shortcut for "Eval vm_compute in <expr>".
+- New command "Fail <command>." interprets a command and is successful iff
+ the command fails on an error (but not an anomaly). Handy for tests and
+ illustration of wrong commands.
+- Most commands referring to constant (e.g. Print or About) now support
+ referring to the constant by a notation string.
+- New option "Boolean Equality Schemes" to make generation of boolean
+ equality automatic for datatypes (together with option "Decidable
+ Equality Schemes", this replaces deprecated option "Equality Scheme").
+- Made support for automatic generation of case analysis schemes available
+ to user (governed by option "Set Case Analysis Schemes").
+- New command "(Global?) Generalizable [All|No] Variable(s)? ident(s)?" to
+ declare which identifiers are generalizable in `{} and `() binders.
+- New command "Print Opaque Dependencies" to display opaque constants in
+ addition to all variables, parameters or axioms a theorem or
+ definition relies on.
+- New command "Declare Reduction <id> := <conv_expr>", allowing to write
+ later "Eval <id> in ...". This command accepts a Local variant.
+- Syntax of Implicit Type now supports more than one block of variables of
+ a given type.
+- Command "Canonical Structure" now warns when it has no effects.
+- Commands of the form "Set X" or "Unset X" now support "Local" and "Global"
+ prefixes.
+
+Library
+
+- Use "standard" Coq names for the properties of eq and identity
+ (e.g. refl_equal is now eq_refl). Support for compatibility is provided.
+- The function Compare_dec.nat_compare is now defined directly,
+ instead of relying on lt_eq_lt_dec. The earlier version is still
+ available under the name nat_compare_alt.
+- Lemmas in library Relations and Reals have been homogenized a bit.
+- The implicit argument of Logic.eq is now maximally inserted, allowing
+ to simply write "eq" instead of "@eq _" in morphism signatures.
+- Wrongly named lemmas (Zlt_gt_succ and Zlt_succ_gt) fixed (potential source
+ of incompatibilities)
+- List library:
+ - Definitions of list, length and app are now in Init/Datatypes.
+ Support for compatibility is provided.
+ - Definition of Permutation is now in Sorting/Permtation.v
+ - Some other light revisions and extensions (possible source
+ of incompatibilities solvable by qualifying names accordingly).
+- In ListSet, set_map has been fixed (source of incompatibilities if used).
+- Sorting library:
+ - new mergesort of worst-case complexity O(n*ln(n)) made available in
+ Mergesort.v;
+ - former notion of permutation up to setoid from Permutation.v is
+ deprecated and moved to PermutSetoid.v;
+ - heapsort from Heap.v of worst-case complexity O(n*n) is deprecated;
+ - new file Sorted.v for some definitions of being sorted.
+- Structure library. This new library is meant to contain generic
+ structures such as types with equalities or orders, either
+ in Module version (for now) or Type Classes (still to do):
+ - DecidableType.v and OrderedType.v: initial notions for FSets/FMaps,
+ left for compatibility but considered as deprecated.
+ - Equalities.v and Orders.v: evolutions of the previous files,
+ with fine-grain Module architecture, many variants, use of
+ Equivalence and other relevant Type Classes notions.
+ - OrdersTac.v: a generic tactic for solving chains of (in)equalities
+ over variables. See {Nat,N,Z,P}OrderedType.v for concrete instances.
+ - GenericMinMax.v: any ordered type can be equipped with min and max.
+ We derived here all the generic properties of these functions.
+- MSets library: an important evolution of the FSets library.
+ "MSets" stands for Modular (Finite) Sets, by contrast with a forthcoming
+ library of Class (Finite) Sets contributed by S. Lescuyer which will be
+ integrated with the next release of Coq. The main features of MSets are:
+ - The use of Equivalence, Proper and other Type Classes features
+ easing the handling of setoid equalities.
+ - The interfaces are now stated in iff-style. Old specifications
+ are now derived properties.
+ - The compare functions are now pure, and return a "comparison" value.
+ Thanks to the CompSpec inductive type, reasoning on them remains easy.
+ - Sets structures requiring invariants (i.e. sorted lists) are
+ built first as "Raw" sets (pure objects and separate proofs) and
+ attached with their proofs thanks to a generic functor. "Raw" sets
+ have now a proper interface and can be manipulated directly.
+ Note: No Maps yet in MSets. The FSets library is still provided
+ for compatibility, but will probably be considered as deprecated in the
+ next release of Coq.
+- Numbers library:
+ - The abstract layer (NatInt, Natural/Abstract, Integer/Abstract) has
+ been simplified and enhance thanks to new features of the module
+ system such as Include (see above). It has been extended to Euclidean
+ division (three flavors for integers: Trunc, Floor and Math).
+ - The arbitrary-large efficient numbers (BigN, BigZ, BigQ) has also
+ been reworked. They benefit from the abstract layer improvements
+ (especially for div and mod). Note that some specifications have
+ slightly changed (compare, div, mod, shift{r,l}). Ring/Field should
+ work better (true recognition of constants).
+
+Tools
+
+- Option -R now supports binding Coq root read-only.
+- New coqtop/coqc option -beautify to reformat .v files (usable
+ e.g. to globally update notations).
+- New tool beautify-archive to beautify a full archive of developments.
+- New coqtop/coqc option -compat X.Y to simulate the general behavior
+ of previous versions of Coq (provides e.g. support for 8.2 compatibility).
+
+Coqdoc
+
+- List have been revamped. List depth and scope is now determined by
+ an "offside" whitespace rule.
+- Text may be italicized by placing it in _underscores_.
+- The "--index <string>" flag changes the filename of the index.
+- The "--toc-depth <int>" flag limits the depth of headers which are
+ included in the table of contents.
+- The "--lib-name <string>" flag prints "<string> Foo" instead of
+ "Library Foo" where library titles are called for. The
+ "--no-lib-name" flag eliminates the extra title.
+- New option "--parse-comments" to allow parsing of regular "(* *)"
+ comments.
+- New option "--plain-comments" to disable interpretation inside comments.
+- New option "--interpolate" to try and typeset identifiers in Coq escapings
+ using the available globalization information.
+- New option "--external url root" to refer to external libraries.
+- Links to section variables and notations now supported.
+
+Internal infrastructure
+
+- To avoid confusion with the repository of user's contributions,
+ the subdirectory "contrib" has been renamed into "plugins".
+ On platforms supporting ocaml native dynlink, code located there
+ is built as loadable plugins for coqtop.
+- An experimental build mechanism via ocamlbuild is provided.
+ From the top of the archive, run ./configure as usual, and
+ then ./build. Feedback about this build mechanism is most welcome.
+ Compiling Coq on platforms such as Windows might be simpler
+ this way, but this remains to be tested.
+- The Makefile system has been simplified and factorized with
+ the ocamlbuild system. In particular "make" takes advantage
+ of .mllib files for building .cma/.cmxa. The .vo files to
+ compile are now listed in several vo.itarget files.
+
+Changes from V8.1 to V8.2
+=========================
+
+Language
+
+- If a fixpoint is not written with an explicit { struct ... }, then
+ all arguments are tried successively (from left to right) until one is
+ found that satisfies the structural decreasing condition.
+- New experimental typeclass system giving ad-hoc polymorphism and
+ overloading based on dependent records and implicit arguments.
+- New syntax "let 'pat := b in c" for let-binding using irrefutable patterns.
+- New syntax "forall {A}, T" for specifying maximally inserted implicit
+ arguments in terms.
+- Sort of Record/Structure, Inductive and CoInductive defaults to Type
+ if omitted.
+- (Co)Inductive types can be defined as records
+ (e.g. "CoInductive stream := { hd : nat; tl : stream }.")
+- New syntax "Theorem id1:t1 ... with idn:tn" for proving mutually dependent
+ statements.
+- Support for sort-polymorphism on constants denoting inductive types.
+- Several evolutions of the module system (handling of module aliases,
+ functorial module types, an Include feature, etc).
+- Prop now a subtype of Set (predicative and impredicative forms).
+- Recursive inductive types in Prop with a single constructor of which
+ all arguments are in Prop is now considered to be a singleton
+ type. It consequently supports all eliminations to Prop, Set and Type.
+ As a consequence, Acc_rect has now a more direct proof [possible source
+ of easily fixed incompatibility in case of manual definition of a recursor
+ in a recursive singleton inductive type].
+
+Vernacular commands
+
+- Added option Global to "Arguments Scope" for section surviving.
+- Added option "Unset Elimination Schemes" to deactivate the automatic
+ generation of elimination schemes.
+- Modification of the Scheme command so you can ask for the name to be
+ automatically computed (e.g. Scheme Induction for nat Sort Set).
+- New command "Combined Scheme" to build combined mutual induction
+ principles from existing mutual induction principles.
+- New command "Scheme Equality" to build a decidable (boolean) equality
+ for simple inductive datatypes and a decision property over this equality
+ (e.g. Scheme Equality for nat).
+- Added option "Set Equality Scheme" to make automatic the declaration
+ of the boolean equality when possible.
+- Source of universe inconsistencies now printed when option
+ "Set Printing Universes" is activated.
+- New option "Set Printing Existential Instances" for making the display of
+ existential variable instances explicit.
+- Support for option "[id1 ... idn]", and "-[id1 ... idn]", for the
+ "compute"/"cbv" reduction strategy, respectively meaning reduce only, or
+ everything but, the constants id1 ... idn. "lazy" alone or followed by
+ "[id1 ... idn]", and "-[id1 ... idn]" also supported, meaning apply
+ all of beta-iota-zeta-delta, possibly restricting delta.
+- New command "Strategy" to control the expansion of constants during
+ conversion tests. It generalizes commands Opaque and Transparent by
+ introducing a range of levels. Lower levels are assigned to constants
+ that should be expanded first.
+- New options Global and Local to Opaque and Transparent.
+- New command "Print Assumptions" to display all variables, parameters
+ or axioms a theorem or definition relies on.
+- "Add Rec LoadPath" now provides references to libraries using partially
+ qualified names (this holds also for coqtop/coqc option -R).
+- SearchAbout supports negated search criteria, reference to logical objects
+ by their notation, and more generally search of subterms.
+- "Declare ML Module" now allows to import .cmxs files when Coq is
+ compiled in native code with a version of OCaml that supports native
+ Dynlink (>= 3.11).
+- Specific sort constraints on Record now taken into account.
+- "Print LoadPath" supports a path argument to filter the display.
+
+Libraries
+
+- Several parts of the libraries are now in Type, in particular FSets,
+ SetoidList, ListSet, Sorting, Zmisc. This may induce a few
+ incompatibilities. In case of trouble while fixing existing development,
+ it may help to simply declare Set as an alias for Type (see file
+ SetIsType).
+- New arithmetical library in theories/Numbers. It contains:
+ * an abstract modular development of natural and integer arithmetics
+ in Numbers/Natural/Abstract and Numbers/Integer/Abstract
+ * an implementation of efficient computational bounded and unbounded
+ integers that can be mapped to processor native arithmetics.
+ See Numbers/Cyclic/Int31 for 31-bit integers and Numbers/Natural/BigN
+ for unbounded natural numbers and Numbers/Integer/BigZ for unbounded
+ integers.
+ * some proofs that both older libraries Arith, ZArith and NArith and
+ newer BigN and BigZ implement the abstract modular development.
+ This allows in particular BigN and BigZ to already come with a
+ large database of basic lemmas and some generic tactics (ring),
+ This library has still an experimental status, as well as the
+ processor-acceleration mechanism, but both its abstract and its
+ concrete parts are already quite usable and could challenge the use
+ of nat, N and Z in actual developments. Moreover, an extension of
+ this framework to rational numbers is ongoing, and an efficient
+ Q structure is already provided (see Numbers/Rational/BigQ), but
+ this part is currently incomplete (no abstract layer and generic
+ lemmas).
+- Many changes in FSets/FMaps. In practice, compatibility with earlier
+ version should be fairly good, but some adaptations may be required.
+ * Interfaces of unordered ("weak") and ordered sets have been factorized
+ thanks to new features of Coq modules (in particular Include), see
+ FSetInterface. Same for maps. Hints in these interfaces have been
+ reworked (they are now placed in a "set" database).
+ * To allow full subtyping between weak and ordered sets, a field
+ "eq_dec" has been added to OrderedType. The old version of OrderedType
+ is now called MiniOrderedType and functor MOT_to_OT allow to
+ convert to the new version. The interfaces and implementations
+ of sets now contain also such a "eq_dec" field.
+ * FSetDecide, contributed by Aaron Bohannon, contains a decision
+ procedure allowing to solve basic set-related goals (for instance,
+ is a point in a particular set ?). See FSetProperties for examples.
+ * Functors of properties have been improved, especially the ones about
+ maps, that now propose some induction principles. Some properties
+ of fold need less hypothesis.
+ * More uniformity in implementations of sets and maps: they all use
+ implicit arguments, and no longer export unnecessary scopes (see
+ bug #1347)
+ * Internal parts of the implementations based on AVL have evolved a
+ lot. The main files FSetAVL and FMapAVL are now much more
+ lightweight now. In particular, minor changes in some functions
+ has allowed to fully separate the proofs of operational
+ correctness from the proofs of well-balancing: well-balancing is
+ critical for efficiency, but not anymore for proving that these
+ trees implement our interfaces, hence we have moved these proofs
+ into appendix files FSetFullAVL and FMapFullAVL. Moreover, a few
+ functions like union and compare have been modified in order to be
+ structural yet efficient. The appendix files also contains
+ alternative versions of these few functions, much closer to the
+ initial Ocaml code and written via the Function framework.
+- Library IntMap, subsumed by FSets/FMaps, has been removed from
+ Coq Standard Library and moved into a user contribution Cachan/IntMap
+- Better computational behavior of some constants (eq_nat_dec and
+ le_lt_dec more efficient, Z_lt_le_dec and Positive_as_OT.compare
+ transparent, ...) (exceptional source of incompatibilities).
+- Boolean operators moved from module Bool to module Datatypes (may need
+ to rename qualified references in script and force notations || and &&
+ to be at levels 50 and 40 respectively).
+- The constructors xI and xO of type positive now have postfix notations
+ "~1" and "~0", allowing to write numbers in binary form easily, for instance
+ 6 is 1~1~0 and 4*p is p~0~0 (see BinPos.v).
+- Improvements to NArith (Nminus, Nmin, Nmax), and to QArith (in particular
+ a better power function).
+- Changes in ZArith: several additional lemmas (used in theories/Numbers),
+ especially in Zdiv, Znumtheory, Zpower. Moreover, many results in
+ Zdiv have been generalized: the divisor may simply be non-null
+ instead of strictly positive (see lemmas with name ending by
+ "_full"). An alternative file ZOdiv proposes a different behavior
+ (the one of Ocaml) when dividing by negative numbers.
+- Changes in Arith: EqNat and Wf_nat now exported from Arith, some
+ constructions on nat that were outside Arith are now in (e.g. iter_nat).
+- In SetoidList, eqlistA now expresses that two lists have similar elements
+ at the same position, while the predicate previously called eqlistA
+ is now equivlistA (this one only states that the lists contain the same
+ elements, nothing more).
+- Changes in Reals:
+ * Most statement in "sigT" (including the
+ completeness axiom) are now in "sig" (in case of incompatibility,
+ use proj1_sig instead of projT1, sig instead of sigT, etc).
+ * More uniform naming scheme (identifiers in French moved to English,
+ consistent use of 0 -- zero -- instead of O -- letter O --, etc).
+ * Lemma on prod_f_SO is now on prod_f_R0.
+ * Useless hypothesis of ln_exists1 dropped.
+ * New Rlogic.v states a few logical properties about R axioms.
+ * RIneq.v extended and made cleaner.
+- Slight restructuration of the Logic library regarding choice and classical
+ logic. Addition of files providing intuitionistic axiomatizations of
+ descriptions: Epsilon.v, Description.v and IndefiniteDescription.v.
+- Definition of pred and minus made compatible with the structural
+ decreasing criterion for use in fixpoints.
+- Files Relations/Rstar.v and Relations/Newman.v moved out to the user
+ contribution repository (contribution CoC_History). New lemmas about
+ transitive closure added and some bound variables renamed (exceptional
+ risk of incompatibilities).
+- Syntax for binders in terms (e.g. for "exists") supports anonymous names.
+
+Notations, coercions, implicit arguments and type inference
+
+- More automation in the inference of the return clause of dependent
+ pattern-matching problems.
+- Experimental allowance for omission of the clauses easily detectable as
+ impossible in pattern-matching problems.
+- Improved inference of implicit arguments.
+- New options "Set Maximal Implicit Insertion", "Set Reversible Pattern
+ Implicit", "Set Strongly Strict Implicit" and "Set Printing Implicit
+ Defensive" for controlling inference and use of implicit arguments.
+- New modifier in "Implicit Arguments" to force an implicit argument to
+ be maximally inserted.
+- New modifier of "Implicit Arguments" to enrich the set of implicit arguments.
+- New options Global and Local to "Implicit Arguments" for section
+ surviving or non export outside module.
+- Level "constr" moved from 9 to 8.
+- Structure/Record now printed as Record (unless option Printing All is set).
+- Support for parametric notations defining constants.
+- Insertion of coercions below product types refrains to unfold
+ constants (possible source of incompatibility).
+- New support for fix/cofix in notations.
+
+Tactic Language
+
+- Second-order pattern-matching now working in Ltac "match" clauses
+ (syntax for second-order unification variable is "@?X").
+- Support for matching on let bindings in match context using syntax
+ "H := body" or "H := body : type".
+- Ltac accepts integer arguments (syntax is "ltac:nnn" for nnn an integer).
+- The general sequence tactical "expr_0 ; [ expr_1 | ... | expr_n ]"
+ is extended so that at most one expr_i may have the form "expr .."
+ or just "..". Also, n can be different from the number of subgoals
+ generated by expr_0. In this case, the value of expr (or idtac in
+ case of just "..") is applied to the intermediate subgoals to make
+ the number of tactics equal to the number of subgoals.
+- A name used as the name of the parameter of a lemma (like f in
+ "apply f_equal with (f:=t)") is now interpreted as a ltac variable
+ if such a variable exists (this is a possible source of
+ incompatibility and it can be fixed by renaming the variables of a
+ ltac function into names that do not clash with the lemmas
+ parameter names used in the tactic).
+- New syntax "Ltac tac ::= ..." to rebind a tactic to a new expression.
+- "let rec ... in ... " now supported for expressions without explicit
+ parameters; interpretation is lazy to the contrary of "let ... in ...";
+ hence, the "rec" keyword can be used to turn the argument of a
+ "let ... in ..." into a lazy one.
+- Patterns for hypotheses types in "match goal" are now interpreted in
+ type_scope.
+- A bound variable whose name is not used elsewhere now serves as
+ metavariable in "match" and it gets instantiated by an identifier
+ (allow e.g. to extract the name of a statement like "exists x, P x").
+- New printing of Ltac call trace for better debugging.
+
+Tactics
+
+- New tactics "apply -> term", "apply <- term", "apply -> term in
+ ident", "apply <- term in ident" for applying equivalences (iff).
+- Slight improvement of the hnf and simpl tactics when applied on
+ expressions with explicit occurrences of match or fix.
+- New tactics "eapply in", "erewrite", "erewrite in".
+- New tactics "ediscriminate", "einjection", "esimplify_eq".
+- Tactics "discriminate", "injection", "simplify_eq" now support any
+ term as argument. Clause "with" is also supported.
+- Unfoldable references can be given by notation's string rather than by name
+ in unfold.
+- The "with" arguments are now typed using informations from the current goal:
+ allows support for coercions and more inference of implicit arguments.
+- Application of "f_equal"-style lemmas works better.
+- Tactics elim, case, destruct and induction now support variants eelim,
+ ecase, edestruct and einduction.
+- Tactics destruct and induction now support the "with" option and the
+ "in" clause option. If the option "in" is used, an equality is added
+ to remember the term to which the induction or case analysis applied
+ (possible source of parsing incompatibilities when destruct or induction is
+ part of a let-in expression in Ltac; extra parentheses are then required).
+- New support for "as" clause in tactics "apply in" and "eapply in".
+- Some new intro patterns:
+ * intro pattern "?A" genererates a fresh name based on A.
+ Caveat about a slight loss of compatibility:
+ Some intro patterns don't need space between them. In particular
+ intros ?a?b used to be legal and equivalent to intros ? a ? b. Now it
+ is still legal but equivalent to intros ?a ?b.
+ * intro pattern "(A & ... & Y & Z)" synonym to "(A,....,(Y,Z)))))"
+ for right-associative constructs like /\ or exists.
+- Several syntax extensions concerning "rewrite":
+ * "rewrite A,B,C" can be used to rewrite A, then B, then C. These rewrites
+ occur only on the first subgoal: in particular, side-conditions of the
+ "rewrite A" are not concerned by the "rewrite B,C".
+ * "rewrite A by tac" allows to apply tac on all side-conditions generated by
+ the "rewrite A".
+ * "rewrite A at n" allows to select occurrences to rewrite: rewrite only
+ happen at the n-th exact occurrence of the first successful matching of
+ A in the goal.
+ * "rewrite 3 A" or "rewrite 3!A" is equivalent to "rewrite A,A,A".
+ * "rewrite !A" means rewriting A as long as possible (and at least once).
+ * "rewrite 3?A" means rewriting A at most three times.
+ * "rewrite ?A" means rewriting A as long as possible (possibly never).
+ * many of the above extensions can be combined with each other.
+- Introduction patterns better respect the structure of context in presence of
+ missing or extra names in nested disjunction-conjunction patterns [possible
+ source of rare incompatibilities].
+- New syntax "rename a into b, c into d" for "rename a into b; rename c into d"
+- New tactics "dependent induction/destruction H [ generalizing id_1 .. id_n ]"
+ to do induction-inversion on instantiated inductive families à la BasicElim.
+- Tactics "apply" and "apply in" now able to reason modulo unfolding of
+ constants (possible source of incompatibility in situations where apply
+ may fail, e.g. as argument of a try or a repeat and in a ltac function);
+ versions that do not unfold are renamed into "simple apply" and
+ "simple apply in" (usable for compatibility or for automation).
+- Tactics "apply" and "apply in" now able to traverse conjunctions and to
+ select the first matching lemma among the components of the conjunction;
+ tactic "apply" also able to apply lemmas of conclusion an empty type.
+- Tactic "apply" now supports application of several lemmas in a row.
+- Tactics "set" and "pose" can set functions using notation "(f x1..xn := c)".
+- New tactic "instantiate" (without argument).
+- Tactic firstorder "with" and "using" options have their meaning swapped for
+ consistency with auto/eauto (source of incompatibility).
+- Tactic "generalize" now supports "at" options to specify occurrences
+ and "as" options to name the quantified hypotheses.
+- New tactic "specialize H with a" or "specialize (H a)" allows to transform
+ in-place a universally-quantified hypothesis (H : forall x, T x) into its
+ instantiated form (H : T a). Nota: "specialize" was in fact there in earlier
+ versions of Coq, but was undocumented, and had a slightly different behavior.
+- New tactic "contradict H" can be used to solve any kind of goal as long as
+ the user can provide afterwards a proof of the negation of the hypothesis H.
+ If H is already a negation, say ~T, then a proof of T is asked.
+ If the current goal is a negation, say ~U, then U is saved in H afterwards,
+ hence this new tactic "contradict" extends earlier tactic "swap", which is
+ now obsolete.
+- Tactics f_equal is now done in ML instead of Ltac: it now works on any
+ equality of functions, regardless of the arity of the function.
+- New options "before id", "at top", "at bottom" for tactics "move"/"intro".
+- Some more debug of reflexive omega (romega), and internal clarifications.
+ Moreover, romega now has a variant "romega with *" that can be also used
+ on non-Z goals (nat, N, positive) via a call to a translation tactic named
+ zify (its purpose is to Z-ify your goal...). This zify may also be used
+ independently of romega.
+- Tactic "remember" now supports an "in" clause to remember only selected
+ occurrences of a term.
+- Tactic "pose proof" supports name overwriting in case of specialization of an
+ hypothesis.
+- Semi-decision tactic "jp" for first-order intuitionistic logic moved to user
+ contributions (subsumed by "firstorder").
+
+Program
+
+- Moved useful tactics in theories/Program and documented them.
+- Add Program.Basics which contains standard definitions for functional
+ programming (id, apply, flip...)
+- More robust obligation handling, dependent pattern-matching and
+ well-founded definitions.
+- New syntax " dest term as pat in term " for destructing objects using
+ an irrefutable pattern while keeping equalities (use this instead of
+ "let" in Programs).
+- Program CoFixpoint is accepted, Program Fixpoint uses the new way to infer
+ which argument decreases structurally.
+- Program Lemma, Axiom etc... now permit to have obligations in the statement
+ iff they can be automatically solved by the default tactic.
+- Renamed "Obligations Tactic" command to "Obligation Tactic".
+- New command "Preterm [ of id ]" to see the actual term fed to Coq for
+ debugging purposes.
+- New option "Transparent Obligations" to control the declaration of
+ obligations as transparent or opaque. All obligations are now transparent
+ by default, otherwise the system declares them opaque if possible.
+- Changed the notations "left" and "right" to "in_left" and "in_right" to hide
+ the proofs in standard disjunctions, to avoid breaking existing scripts when
+ importing Program. Also, put them in program_scope.
+
+Type Classes
+
+- New "Class", "Instance" and "Program Instance" commands to define
+ classes and instances documented in the reference manual.
+- New binding construct " [ Class_1 param_1 .. param_n, Class_2 ... ] "
+ for binding type classes, usable everywhere.
+- New command " Print Classes " and " Print Instances some_class " to
+ print tables for typeclasses.
+- New default eauto hint database "typeclass_instances" used by the default
+ typeclass instance search tactic.
+- New theories directory "theories/Classes" for standard typeclasses
+ declarations. Module Classes.RelationClasses is a typeclass port of
+ Relation_Definitions plus a generic development of algebra on
+ n-ary heterogeneous predicates.
+
+Setoid rewriting
+
+- Complete (and still experimental) rewrite of the tactic
+ based on typeclasses. The old interface and semantics are
+ almost entirely respected, except:
+
+ - Import Setoid is now mandatory to be able to call setoid_replace
+ and declare morphisms.
+
+ - "-->", "++>" and "==>" are now right associative notations
+ declared at level 55 in scope signature_scope.
+ Their introduction may break existing scripts that defined
+ them as notations with different levels.
+
+ - One needs to use [Typeclasses unfold [cst]] if [cst] is used
+ as an abbreviation hiding products in types of morphisms,
+ e.g. if ones redefines [relation] and declares morphisms
+ whose type mentions [relation].
+
+ - The [setoid_rewrite]'s semantics change when rewriting with
+ a lemma: it can rewrite two different instantiations of the lemma
+ at once. Use [setoid_rewrite H at 1] for (almost) the usual semantics.
+ [setoid_rewrite] will also try to rewrite under binders now, and can
+ succeed on different terms than before. In particular, it will unify under
+ let-bound variables. When called through [rewrite], the semantics are
+ unchanged though.
+
+ - [Add Morphism term : id] has different semantics when used with
+ parametric morphism: it will try to find a relation on the parameters
+ too. The behavior has also changed with respect to default relations:
+ the most recently declared Setoid/Relation will be used, the documentation
+ explains how to customize this behavior.
+
+ - Parametric Relation and Morphism are declared differently, using the
+ new [Add Parametric] commands, documented in the manual.
+
+ - Setoid_Theory is now an alias to Equivalence, scripts building objects
+ of type Setoid_Theory need to unfold (or "red") the definitions
+ of Reflexive, Symmetric and Transitive in order to get the same goals
+ as before. Scripts which introduced variables explicitely will not break.
+
+ - The order of subgoals when doing [setoid_rewrite] with side-conditions
+ is always the same: first the new goal, then the conditions.
+
+- New standard library modules Classes.Morphisms declares
+ standard morphisms on refl/sym/trans relations.
+ Classes.Morphisms_Prop declares morphisms on propositional
+ connectives and Classes.Morphisms_Relations on generalized predicate
+ connectives. Classes.Equivalence declares notations and tactics
+ related to equivalences and Classes.SetoidTactics defines the
+ setoid_replace tactics and some support for the "Add *" interface,
+ notably the tactic applied automatically before each "Add Morphism"
+ proof.
+
+- User-defined subrelations are supported, as well as higher-order morphisms
+ and rewriting under binders. The tactic is also extensible entirely in Ltac.
+ The documentation has been updated to cover these features.
+
+- [setoid_rewrite] and [rewrite] now support the [at] modifier to select
+ occurrences to rewrite, and both use the [setoid_rewrite] code, even when
+ rewriting with leibniz equality if occurrences are specified.
+
+Extraction
+
+- Improved behavior of the Caml extraction of modules: name clashes should
+ not happen anymore.
+- The command Extract Inductive has now a syntax for infix notations. This
+ allows in particular to map Coq lists and pairs onto Caml ones:
+ Extract Inductive list => list [ "[]" "(::)" ].
+ Extract Inductive prod => "(*)" [ "(,)" ].
+- In pattern matchings, a default pattern "| _ -> ..." is now used whenever
+ possible if several branches are identical. For instance, functions
+ corresponding to decidability of equalities are now linear instead of
+ quadratic.
+- A new instruction Extraction Blacklist id1 .. idn allows to prevent filename
+ conflits with existing code, for instance when extracting module List
+ to Ocaml.
+
+CoqIDE
+
+- CoqIDE font defaults to monospace so as indentation to be meaningful.
+- CoqIDE supports nested goals and any other kind of declaration in the middle
+ of a proof.
+- Undoing non-tactic commands in CoqIDE works faster.
+- New CoqIDE menu for activating display of various implicit informations.
+- Added the possibility to choose the location of tabs in coqide:
+ (in Edit->Preferences->Misc)
+- New Open and Save As dialogs in CoqIDE which filter *.v files.
+
+Tools
+
+- New stand-alone .vo files verifier "coqchk".
+- Extended -I coqtop/coqc option to specify a logical dir: "-I dir -as coqdir".
+- New coqtop/coqc option -exclude-dir to exclude subdirs for option -R.
+- The binary "parser" has been renamed to "coq-parser".
+- Improved coqdoc and dump of globalization information to give more
+ meta-information on identifiers. All categories of Coq definitions are
+ supported, which makes typesetting trivial in the generated documentation.
+ Support for hyperlinking and indexing developments in the tex output
+ has been implemented as well.
+
+Miscellaneous
+
+- Coq installation provides enough files so that Ocaml's extensions need not
+ the Coq sources to be compiled (this assumes O'Caml 3.10 and Camlp5).
+- New commands "Set Whelp Server" and "Set Whelp Getter" to customize the
+ Whelp search tool.
+- Syntax of "Test Printing Let ref" and "Test Printing If ref" changed into
+ "Test Printing Let for ref" and "Test Printing If for ref".
+- An overhauled build system (new Makefiles); see dev/doc/build-system.txt.
+- Add -browser option to configure script.
+- Build a shared library for the C part of Coq, and use it by default on
+ non-(Windows or MacOS) systems. Bytecode executables are now pure. The
+ behaviour is configurable with -coqrunbyteflags, -coqtoolsbyteflags and
+ -custom configure options.
+- Complexity tests can be skipped by setting the environment variable
+ COQTEST_SKIPCOMPLEXITY.
+
+Changes from V8.1gamma to V8.1
+==============================
+
+Bug fixes
+
+- Many bugs have been fixed (cf coq-bugs web page)
+
+Tactics
+
+- New tactics ring, ring_simplify and new tactic field now able to manage
+ power to a positive integer constant. Tactic ring on Z and R, and
+ field on R manage power (may lead to incompatibilities with V8.1gamma).
+- Tactic field_simplify now applicable in hypotheses.
+- New field_simplify_eq for simplifying field equations into ring equations.
+- Tactics ring, ring_simplify, field, field_simplify and field_simplify_eq
+ all able to apply user-given equations to rewrite monoms on the fly
+ (see documentation).
+
+Libraries
+
+- New file ConstructiveEpsilon.v defining an epsilon operator and
+ proving the axiom of choice constructively for a countable domain
+ and a decidable predicate.
+
+Changes from V8.1beta to V8.1gamma
+==================================
+
+Syntax
+
+- changed parsing precedence of let/in and fun constructions of Ltac:
+ let x := t in e1; e2 is now parsed as let x := t in (e1;e2).
+
+Language and commands
+
+- Added sort-polymorphism for definitions in Type (but finally abandonned).
+- Support for implicit arguments in the types of parameters in
+ (co-)fixpoints and (co-)inductive declarations.
+- Improved type inference: use as much of possible general information.
+ before applying irreversible unification heuristics (allow e.g. to
+ infer the predicate in "(exist _ 0 (refl_equal 0) : {n:nat | n=0 })").
+- Support for Miller-Pfenning's patterns unification in type synthesis
+ (e.g. can infer P such that P x y = phi(x,y)).
+- Support for "where" clause in cofixpoint definitions.
+- New option "Set Printing Universes" for making Type levels explicit.
+
+Tactics
+
+- Improved implementation of the ring and field tactics. For compatibility
+ reasons, the previous tactics are renamed as legacy ring and legacy field,
+ but should be considered as deprecated.
+- New declarative mathematical proof language.
+- Support for argument lists of arbitrary length in Tactic Notation.
+- [rewrite ... in H] now fails if [H] is used either in an hypothesis
+ or in the goal.
+- The semantics of [rewrite ... in *] has been slightly modified (see doc).
+- Support for "as" clause in tactic injection.
+- New forward-reasoning tactic "apply in".
+- Ltac fresh operator now builds names from a concatenation of its arguments.
+- New ltac tactic "remember" to abstract over a subterm and keep an equality
+- Support for Miller-Pfenning's patterns unification in apply/rewrite/...
+ (may lead to few incompatibilities - generally now useless tactic calls).
+
+Bug fixes
+
+- Fix for notations involving basic "match" expressions.
+- Numerous other bugs solved (a few fixes may lead to incompatibilities).
+
+
+Changes from V8.0 to V8.1beta
+=============================
+
+Logic
+
+- Added sort-polymorphism on inductive families
+- Allowance for recursively non uniform parameters in inductive types
+
+Syntax
+
+- No more support for version 7 syntax and for translation to version 8 syntax.
+- In fixpoints, the { struct ... } annotation is not mandatory any more when
+ only one of the arguments has an inductive type
+- Added disjunctive patterns in match-with patterns
+- Support for primitive interpretation of string literals
+- Extended support for Unicode ranges
+
+Vernacular commands
+
+- Added "Print Ltac qualid" to print a user defined tactic.
+- Added "Print Rewrite HintDb" to print the content of a DB used by
+ autorewrite.
+- Added "Print Canonical Projections".
+- Added "Example" as synonym of "Definition".
+- Added "Proposition" and "Corollary" as extra synonyms of "Lemma".
+- New command "Whelp" to send requests to the Helm database of proofs
+ formalized in the Calculus of Inductive Constructions.
+- Command "functional induction" has been re-implemented from the new
+ "Function" command.
+
+Ltac and tactic syntactic extensions
+
+- New primitive "external" for communication with tool external to Coq
+- New semantics for "match t with": if a clause returns a
+ tactic, it is now applied to the current goal. If it fails, the next
+ clause or next matching subterm is tried (i.e. it behaves as "match
+ goal with" does). The keyword "lazymatch" can be used to delay the
+ evaluation of tactics occurring in matching clauses.
+- Hint base names can be parametric in auto and trivial.
+- Occurrence values can be parametric in unfold, pattern, etc.
+- Added entry constr_may_eval for tactic extensions.
+- Low-priority term printer made available in ML-written tactic extensions.
+- "Tactic Notation" extended to allow notations of tacticals.
+
+Tactics
+
+- New implementation and generalization of [setoid_]* (setoid_rewrite,
+ setoid_symmetry, setoid_transitivity, setoid_reflexivity and autorewite).
+ New syntax for declaring relations and morphisms (old syntax still working
+ with minor modifications, but deprecated).
+- New implementation (still experimental) of the ring tactic with a built-in
+ notion of coefficients and a better usage of setoids.
+- New conversion tactic "vm_compute": evaluates the goal (or an hypothesis)
+ with a call-by-value strategy, using the compiled version of terms.
+- When rewriting H where H is not directly a Coq equality, search first H for
+ a registered setoid equality before starting to reduce in H. This is unlikely
+ to break any script. Should this happen nonetheless, one can insert manually
+ some "unfold ... in H" before rewriting.
+- Fixed various bugs about (setoid) rewrite ... in ... (in particular bug #5941)
+- "rewrite ... in" now accepts a clause as place where to rewrite instead of
+ juste a simple hypothesis name. For instance:
+ rewrite H in H1,H2 |- * means rewrite H in H1; rewrite H in H2; rewrite H
+ rewrite H in * |- will do try rewrite H in Hi for all hypothesis Hi <> H.
+- Added "dependent rewrite term" and "dependent rewrite term in hyp".
+- Added "autorewrite with ... in hyp [using ...]".
+- Tactic "replace" now accepts a "by" tactic clause.
+- Added "clear - id" to clear all hypotheses except the ones depending in id.
+- The argument of Declare Left Step and Declare Right Step is now a term
+ (it used to be a reference).
+- Omega now handles arbitrary precision integers.
+- Several bug fixes in Reflexive Omega (romega).
+- Idtac can now be left implicit in a [...|...] construct: for instance,
+ [ foo | | bar ] stands for [ foo | idtac | bar ].
+- Fixed a "fold" bug (non critical but possible source of incompatibilities).
+- Added classical_left and classical_right which transforms |- A \/ B into
+ ~B |- A and ~A |- B respectively.
+- Added command "Declare Implicit Tactic" to set up a default tactic to be
+ used to solve unresolved subterms of term arguments of tactics.
+- Better support for coercions to Sortclass in tactics expecting type
+ arguments.
+- Tactic "assert" now accepts "as" intro patterns and "by" tactic clauses.
+- New tactic "pose proof" that generalizes "assert (id:=p)" with intro patterns.
+- New introduction pattern "?" for letting Coq choose a name.
+- Introduction patterns now support side hypotheses (e.g. intros [|] on
+ "(nat -> nat) -> nat" works).
+- New introduction patterns "->" and "<-" for immediate rewriting of
+ introduced hypotheses.
+- Introduction patterns coming after non trivial introduction patterns now
+ force full introduction of the first pattern (e.g. "intros [[|] p]" on
+ "nat->nat->nat" now behaves like "intros [[|?] p]")
+- Added "eassumption".
+- Added option 'using lemmas' to auto, trivial and eauto.
+- Tactic "congruence" is now complete for its intended scope (ground
+ equalities and inequalities with constructors). Furthermore, it
+ tries to equates goal and hypotheses.
+- New tactic "rtauto" solves pure propositional logic and gives a
+ reflective version of the available proof.
+- Numbering of "pattern", "unfold", "simpl", ... occurrences in "match
+ with" made consistent with the printing of the return clause after
+ the term to match in the "match-with" construct (use "Set Printing All"
+ to see hidden occurrences).
+- Generalization of induction "induction x1...xn using scheme" where
+ scheme is an induction principle with complex predicates (like the
+ ones generated by function induction).
+- Some small Ltac tactics has been added to the standard library
+ (file Tactics.v):
+ * f_equal : instead of using the different f_equalX lemmas
+ * case_eq : a "case" without loss of information. An equality
+ stating the current situation is generated in every sub-cases.
+ * swap : for a negated goal ~B and a negated hypothesis H:~A,
+ swap H asks you to prove A from hypothesis B
+ * revert : revert H is generalize H; clear H.
+
+Extraction
+
+- All type parts should now disappear instead of sometimes producing _
+ (for instance in Map.empty).
+- Haskell extraction: types of functions are now printed, better
+ unsafeCoerce mechanism, both for hugs and ghc.
+- Scheme extraction improved, see http://www.pps.jussieu.fr/~letouzey/scheme.
+- Many bug fixes.
+
+Modules
+
+- Added "Locate Module qualid" to get the full path of a module.
+- Module/Declare Module syntax made more uniform.
+- Added syntactic sugar "Declare Module Export/Import" and
+ "Module Export/Import".
+- Added syntactic sugar "Module M(Export/Import X Y: T)" and
+ "Module Type M(Export/Import X Y: T)"
+ (only for interactive definitions)
+- Construct "with" generalized to module paths:
+ T with (Definition|Module) M1.M2....Mn.l := l'.
+
+Notations
+
+- Option "format" aware of recursive notations.
+- Added insertion of spaces by default in recursive notations w/o separators.
+- No more automatic printing box in case of user-provided printing "format".
+- New notation "exists! x:A, P" for unique existence.
+- Notations for specific numerals now compatible with generic notations of
+ numerals (e.g. "1" can be used to denote the unit of a group without
+ hiding 1%nat)
+
+Libraries
+
+- New library on String and Ascii characters (contributed by L. Thery).
+- New library FSets+FMaps of finite sets and maps.
+- New library QArith on rational numbers.
+- Small extension of Zmin.V, new Zmax.v, new Zminmax.v.
+- Reworking and extension of the files on classical logic and
+ description principles (possible incompatibilities)
+- Few other improvements in ZArith potentially exceptionally breaking the
+ compatibility (useless hypothesys of Zgt_square_simpl and
+ Zlt_square_simpl removed; fixed names mentioning letter O instead of
+ digit 0; weaken premises in Z_lt_induction).
+- Restructuration of Eqdep_dec.v and Eqdep.v: more lemmas in Type.
+- Znumtheory now contains a gcd function that can compute within Coq.
+- More lemmas stated on Type in Wf.v, removal of redundant Acc_iter and
+ Acc_iter2.
+- Change of the internal names of lemmas in OmegaLemmas.
+- Acc in Wf.v and clos_refl_trans in Relation_Operators.v now rely on
+ the allowance for recursively non uniform parameters (possible
+ source of incompatibilities: explicit pattern-matching on these
+ types may require to remove the occurrence associated to their
+ recursively non uniform parameter).
+- Coq.List.In_dec has been set transparent (this may exceptionally break
+ proof scripts, set it locally opaque for compatibility).
+- More on permutations of lists in List.v and Permutation.v.
+- List.v has been much expanded.
+- New file SetoidList.v now contains results about lists seen with
+ respect to a setoid equality.
+- Library NArith has been expanded, mostly with results coming from
+ Intmap (for instance a bitwise xor), plus also a bridge between N and
+ Bitvector.
+- Intmap has been reorganized. In particular its address type "addr" is
+ now N. User contributions known to use Intmap have been adapted
+ accordingly. If you're using this library please contact us.
+ A wrapper FMapIntMap now presents Intmap as a particular implementation
+ of FMaps. New developments are strongly encouraged to use either this
+ wrapper or any other implementations of FMap instead of using directly
+ this obsolete Intmap.
+
+Tools
+
+- New semantics for coqtop options ("-batch" expects option "-top dir"
+ for loading vernac file that contains definitions).
+- Tool coq_makefile now removes custom targets that are file names in
+ "make clean"
+- New environment variable COQREMOTEBROWSER to set the command invoked
+ to start the remote browser both in Coq and coqide. Standard syntax:
+ "%s" is the placeholder for the URL.
+
+
+Changes from V8.0beta to V8.0
+=============================
+
+Vernacular commands
+
+- New option "Set Printing All" to deactivate all high-level forms of
+ printing (implicit arguments, coercions, destructing let,
+ if-then-else, notations, projections)
+- "Functional Scheme" and "Functional Induction" extended to polymorphic
+ types and dependent types
+- Notation now allows recursive patterns, hence recovering parts of the
+ fonctionalities of pre-V8 Grammar/Syntax commands
+- Command "Print." discontinued.
+- Redundant syntax "Implicit Arguments On/Off" discontinued
+
+New syntax
+
+- Semantics change of the if-then-else construction in new syntax:
+ "if c then t1 else t2" now stands for
+ "match c with c1 _ ... _ => t1 | c2 _ ... _ => t2 end"
+ with no dependency of t1 and t2 in the arguments of the constructors;
+ this may cause incompatibilities for files translated using coq 8.0beta
+
+Interpretation scopes
+
+- Delimiting key %bool for bool_scope added
+- Import no more needed to activate argument scopes from a module
+
+Tactics and the tactic Language
+
+- Semantics of "assert" is now consistent with the reference manual
+- New tactics stepl and stepr for chaining transitivity steps
+- Tactic "replace ... with ... in" added
+- Intro patterns now supported in Ltac (parsed with prefix "ipattern:")
+
+Executables and tools
+
+- Added option -top to change the name of the toplevel module "Top"
+- Coqdoc updated to new syntax and now part of Coq sources
+- XML exportation tool now exports the structure of vernacular files
+ (cf chapter 13 in the reference manual)
+
+User contributions
+
+- User contributions have been updated to the new syntax
+
+Bug fixes
+
+- Many bugs have been fixed (cf coq-bugs web page)
+
+Changes from V8.0beta old syntax to V8.0beta
+============================================
+
+New concrete syntax
+
+- A completely new syntax for terms
+- A more uniform syntax for tactics and the tactic language
+- A few syntactic changes for vernacular commands
+- A smart automatic translator translating V8.0 files in old syntax to
+ files valid for V8.0
+
+Syntax extensions
+
+- "Grammar" for terms disappears
+- "Grammar" for tactics becomes "Tactic Notation"
+- "Syntax" disappears
+- Introduction of a notion of interpretation scope allowing to use the
+ same notations in various contexts without using specific delimiters
+ (e.g the same expression "4<=3+x" is interpreted either in "nat",
+ "positive", "N" (previously "entier"), "Z", "R", depending on which
+ interpretation scope is currently open) [see documentation for details]
+- Notation now mandatorily requires a precedence and associativity
+ (default was to set precedence to 1 and associativity to none)
+
+Revision of the standard library
+
+- Many lemmas and definitions names have been made more uniform mostly
+ in Arith, NArith, ZArith and Reals (e.g : "times" -> "Pmult",
+ "times_sym" -> "Pmult_comm", "Zle_Zmult_pos_right" ->
+ "Zmult_le_compat_r", "SUPERIEUR" -> "Gt", "ZERO" -> "Z0")
+- Order and names of arguments of basic lemmas on nat, Z, positive and R
+ have been made uniform.
+- Notions of Coq initial state are declared with (strict) implicit arguments
+- eq merged with eqT: old eq disappear, new eq (written =) is old eqT
+ and new eqT is syntactic sugar for new eq (notation == is an alias
+ for = and is written as it, exceptional source of incompatibilities)
+- Similarly, ex, ex2, all, identity are merged with exT, exT2, allT, identityT
+- Arithmetical notations for nat, positive, N, Z, R, without needing
+ any backquote or double-backquotes delimiters.
+- In Lists: new concrete notations; argument of nil is now implicit
+- All changes in the library are taken in charge by the translator
+
+Semantical changes during translation
+
+- Recursive keyword set by default (and no longer needed) in Tactic Definition
+- Set Implicit Arguments is strict by default in new syntax
+- reductions in hypotheses of the form "... in H" now apply to the type
+ also if H is a local definition
+- etc
+
+Gallina
+
+- New syntax of the form "Inductive bool : Set := true, false : bool." for
+ enumerated types
+- Experimental syntax of the form p.(fst) for record projections
+ (activable with option "Set Printing Projections" which is
+ recognized by the translator)
+
+Known problems of the automatic translation
+
+- iso-latin-1 characters are no longer supported: move your files to
+ 7-bits ASCII or unicode before translation (swith to unicode is
+ automatically done if a file is loaded and saved again by coqide)
+- Renaming in ZArith: incompatibilities in Coq user contribs due to
+ merging names INZ, from Reals, and inject_nat.
+- Renaming and new lemmas in ZArith: may clash with names used by users
+- Restructuration of ZArith: replace requirement of specific modules
+ in ZArith by "Require Import ZArith_base" or "Require Import ZArith"
+- Some implicit arguments must be made explicit before translation: typically
+ for "length nil", the implicit argument of length must be made explicit
+- Grammar rules, Infix notations and V7.4 Notations must be updated wrt the
+ new scheme for syntactic extensions (see translator documentation)
+- Unsafe for annotation Cases when constructors coercions are used or when
+ annotations are eta-reduced predicates
+
+
+Changes from V7.4 to V8.0beta old syntax
+========================================
+
+Logic
+
+- Set now predicative by default
+- New option -impredicative-set to set Set impredicative
+- The standard library doesn't need impredicativity of Set and is
+ compatible with the classical axioms which contradict Set impredicativity
+
+Syntax for arithmetic
+
+- Notation "=" and "<>" in Z and R are no longer implicitly in Z or R
+ (with possible introduction of a coercion), use <Z>...=... or
+ <Z>...<>... instead
+- Locate applied to a simple string (e.g. "+") searches for all
+ notations containing this string
+
+Vernacular commands
+
+- "Declare ML Module" now allows to import .cma files. This avoids to use a
+ bunch of "Declare ML Module" statements when using several ML files.
+- "Set Printing Width n" added, allows to change the size of width printing.
+- "Implicit Variables Type x,y:t" (new syntax: "Implicit Types x y:t")
+ assigns default types for binding variables.
+- Declarations of Hints and Notation now accept a "Local" flag not to
+ be exported outside the current file even if not in section
+- "Print Scopes" prints all notations
+- New command "About name" for light printing of type, implicit arguments, etc.
+- New command "Admitted" to declare incompletely proven statement as axioms
+- New keyword "Conjecture" to declare an axiom intended to be provable
+- SearchAbout can now search for lemmas referring to more than one constant
+ and on substrings of the name of the lemma
+- "Print Implicit" displays the implicit arguments of a constant
+- Locate now searches for all names having a given suffix
+- New command "Functional Scheme" for building an induction principle
+ from a function defined by case analysis and fix.
+
+Commands
+
+- new coqtop/coqc option -dont-load-proofs not to load opaque proofs in memory
+
+Implicit arguments
+
+- Inductive in sections declared with implicits now "discharged" with
+ implicits (like constants and variables)
+- Implicit Arguments flags are now synchronous with reset
+- New switch "Unset/Set Printing Implicits" (new syntax: "Unset/Set Printing
+ Implicit") to globally control printing of implicits
+
+Grammar extensions
+
+- Many newly supported UTF-8 encoded unicode blocks
+ - Greek letters (0380-03FF), Hebrew letters (U05D0-05EF), letter-like
+ symbols (2100-214F, that includes double N,Z,Q,R), prime
+ signs (from 2080-2089) and characters from many written languages
+ are valid in identifiers
+ - mathematical operators (2200-22FF), supplemental mathematical
+ operators (2A00-2AFF), miscellaneous technical (2300-23FF that
+ includes sqrt symbol), miscellaneous symbols (2600-26FF), arrows
+ (2190-21FF and 2900-297F), invisible mathematical operators (from
+ 2080-2089), ... are valid symbols
+
+Library
+
+- New file about the factorial function in Arith
+- An additional elimination Acc_iter for Acc, simplier than Acc_rect.
+ This new elimination principle is used for definition well_founded_induction.
+- New library NArith on binary natural numbers
+- R is now of type Set
+- Restructuration in ZArith library
+ - "true_sub" used in Zplus now a definition, not a local one (source
+ of incompatibilities in proof referring to true_sub, may need extra Unfold)
+ - Some lemmas about minus moved from fast_integer to Arith/Minus.v
+ (le_minus, lt_mult_left) (theoretical source of incompatibilities)
+ - Several lemmas moved from auxiliary.v and zarith_aux.v to
+ fast_integer.v (theoretical source of incompatibilities)
+ - Variables names of iff_trans changed (source of incompatibilities)
+ - ZArith lemmas named OMEGA something or fast_ something, and lemma new_var
+ are now out of ZArith (except OMEGA2)
+ - Redundant ZArith lemmas have been renamed: for the following pairs,
+ use the second name (Zle_Zmult_right2, Zle_mult_simpl), (OMEGA2,
+ Zle_0_plus), (Zplus_assoc_l, Zplus_assoc), (Zmult_one, Zmult_1_n),
+ (Zmult_assoc_l, Zmult_assoc), (Zmult_minus_distr, Zmult_Zminus_distr_l)
+ (add_un_double_moins_un_xO, is_double_moins_un),
+ (Rlt_monotony_rev,Rlt_monotony_contra) (source of incompatibilities)
+- Few minor changes (no more implicit arguments in
+ Zmult_Zminus_distr_l and Zmult_Zminus_distr_r, lemmas moved from
+ Zcomplements to other files) (rare source of incompatibilities)
+- New lemmas provided by users added
+
+Tactic language
+
+- Fail tactic now accepts a failure message
+- Idtac tactic now accepts a message
+- New primitive tactic "FreshId" (new syntax: "fresh") to generate new names
+- Debugger prints levels of calls
+
+Tactics
+
+- Replace can now replace proofs also
+- Fail levels are now decremented at "Match Context" blocks only and
+ if the right-hand-side of "Match term With" are tactics, these
+ tactics are never evaluated immediately and do not induce
+ backtracking (in contrast with "Match Context")
+- Quantified names now avoid global names of the current module (like
+ Intro names did) [source of rare incompatibilities: 2 changes in the set of
+ user contribs]
+- NewDestruct/NewInduction accepts intro patterns as introduction names
+- NewDestruct/NewInduction now work for non-inductive type using option "using"
+- A NewInduction naming bug for inductive types with functional
+ arguments (e.g. the accessibility predicate) has been fixed (source
+ of incompatibilities)
+- Symmetry now applies to hypotheses too
+- Inversion now accept option "as [ ... ]" to name the hypotheses
+- Contradiction now looks also for contradictory hypotheses stating ~A and A
+ (source of incompatibility)
+- "Contradiction c" try to find an hypothesis in context which
+ contradicts the type of c
+- Ring applies to new library NArith (require file NArithRing)
+- Field now works on types in Set
+- Auto with reals now try to replace le by ge (Rge_le is no longer an
+ immediate hint), resulting in shorter proofs
+- Instantiate now works in hyps (syntax : Instantiate in ...)
+- Some new tactics : EConstructor, ELeft, Eright, ESplit, EExists
+- New tactic "functional induction" to perform case analysis and
+ induction following the definition of a function.
+- Clear now fails when trying to remove a local definition used by
+ a constant appearing in the current goal
+
+Extraction (See details in plugins/extraction/CHANGES)
+
+- The old commands: (Recursive) Extraction Module M.
+ are now: (Recursive) Extraction Library M.
+ To use these commands, M should come from a library M.v
+- The other syntax Extraction & Recursive Extraction now accept
+ module names as arguments.
+
+Bugs
+
+- see coq-bugs server for the complete list of fixed bugs
+
+Miscellaneous
+
+- Implicit parameters of inductive types definition now taken into
+ account for infering other implicit arguments
+
+Incompatibilities
+
+- Persistence of true_sub (4 incompatibilities in Coq user contributions)
+- Variable names of some constants changed for a better uniformity (2 changes
+ in Coq user contributions)
+- Naming of quantified names in goal now avoid global names (2 occurrences)
+- NewInduction naming for inductive types with functional arguments
+ (no incompatibility in Coq user contributions)
+- Contradiction now solve more goals (source of 2 incompatibilities)
+- Merge of eq and eqT may exceptionally result in subgoals now
+ solved automatically
+- Redundant pairs of ZArith lemmas may have different names: it may
+ cause "Apply/Rewrite with" to fail if using the first name of a pair
+ of redundant lemmas (this is solved by renaming the variables bound by
+ "with"; 3 incompatibilities in Coq user contribs)
+- ML programs referring to constants from fast_integer.v must use
+ "Coqlib.gen_constant_modules Coqlib.zarith_base_modules" instead
+
+Changes from V7.3.1 to V7.4
+===========================
+
+Symbolic notations
+
+- Introduction of a notion of scope gathering notations in a consistent set;
+ a notation sets has been developed for nat, Z and R (undocumented)
+- New command "Notation" for declaring notations simultaneously for
+ parsing and printing (see chap 10 of the reference manual)
+- Declarations with only implicit arguments now handled (e.g. the
+ argument of nil can be set implicit; use !nil to refer to nil
+ without arguments)
+- "Print Scope sc" and "Locate ntn" allows to know to what expression a
+ notation is bound
+- New defensive strategy for printing or not implicit arguments to ensure
+ re-type-checkability of the printed term
+- In Grammar command, the only predefined non-terminal entries are ident,
+ global, constr and pattern (e.g. nvar, numarg disappears); the only
+ allowed grammar types are constr and pattern; ast and ast list are no
+ longer supported; some incompatibilities in Grammar: when a syntax is a
+ initial segment of an other one, Grammar does not work, use Notation
+
+Library
+
+- Lemmas in Set from Compare_dec.v (le_lt_dec, ...) and Wf_nat.v
+ (lt_wf_rec, ...) are now transparent. This may be source of
+ incompatibilities.
+- Syntactic Definitions Fst, Snd, Ex, All, Ex2, AllT, ExT, ExT2,
+ ProjS1, ProjS2, Error, Value and Except are turned to
+ notations. They now must be applied (incompatibilities only in
+ unrealistic cases).
+- More efficient versions of Zmult and times (30% faster)
+- Reals: the library is now divided in 6 parts (Rbase, Rfunctions,
+ SeqSeries, Rtrigo, Ranalysis, Integration). New tactics: Sup and
+ RCompute. See Reals.v for details.
+
+Modules
+
+- Beta version, see doc chap 2.5 for commands and chap 5 for theory
+
+Language
+
+- Inductive definitions now accept ">" in constructor types to declare
+ the corresponding constructor as a coercion.
+- Idem for assumptions declarations and constants when the type is mentionned.
+- The "Coercion" and "Canonical Structure" keywords now accept the
+ same syntax as "Definition", i.e. "hyps :=c (:t)?" or "hyps :t".
+- Theorem-like declaration now accepts the syntax "Theorem thm [x:t;...] : u".
+- Remark's and Fact's now definitively behave as Theorem and Lemma: when
+ sections are closed, the full name of a Remark or a Fact has no longer a
+ section part (source of incompatibilities)
+- Opaque Local's (i.e. built by tactics and ended by Qed), do not
+ survive section closing any longer; as a side-effect, Opaque Local's
+ now appear in the local context of proofs; their body is hidden
+ though (source of incompatibilities); use one of Remark/Fact/Lemma/Theorem
+ instead to simulate the old behaviour of Local (the section part of
+ the name is not kept though)
+
+ML tactic and vernacular commands
+
+- "Grammar tactic" and "Grammar vernac" of type "ast" are no longer
+ supported (only "Grammar tactic simple_tactic" of type "tactic"
+ remains available).
+- Concrete syntax for ML written vernacular commands and tactics is
+ now declared at ML level using camlp4 macros TACTIC EXTEND et VERNAC
+ COMMAND EXTEND.
+- "Check n c" now "n:Check c", "Eval n ..." now "n:Eval ..."
+- "Proof with T" (* no documentation *)
+- SearchAbout id - prints all theorems which contain id in their type
+
+Tactic definitions
+
+- Static globalisation of identifiers and global references (source of
+ incompatibilities, especially, Recursive keyword is required for
+ mutually recursive definitions).
+- New evaluation semantics: no more partial evaluation at definition time;
+ evaluation of all Tactic/Meta Definition, even producing terms, expect
+ a proof context to be evaluated (especially "()" is no longer needed).
+- Debugger now shows the nesting level and the reasons of failure
+
+Tactics
+
+- Equality tactics (Rewrite, Reflexivity, Symmetry, Transitivity) now
+ understand JM equality
+- Simpl and Change now apply to subterms also
+- "Simpl f" reduces subterms whose head constant is f
+- Double Induction now referring to hypotheses like "Intros until"
+- "Inversion" now applies also on quantified hypotheses (naming as
+ for Intros until)
+- NewDestruct now accepts terms with missing hypotheses
+- NewDestruct and NewInduction now accept user-provided elimination scheme
+- NewDestruct and NewInduction now accept user-provided introduction names
+- Omega could solve goals such as ~`x<y` |- `x>=y` but failed when the
+ hypothesis was unfolded to `x < y` -> False. This is fixed. In addition,
+ it can also recognize 'False' in the hypothesis and use it to solve the
+ goal.
+- Coercions now handled in "with" bindings
+- "Subst x" replaces all ocurrences of x by t in the goal and hypotheses
+ when an hypothesis x=t or x:=t or t=x exists
+- Fresh names for Assert and Pose now based on collision-avoiding
+ Intro naming strategy (exceptional source of incompatibilities)
+- LinearIntuition (* no documentation *)
+- Unfold expects a correct evaluable argument
+- Clear expects existing hypotheses
+
+Extraction (See details in plugins/extraction/CHANGES and README):
+
+- An experimental Scheme extraction is provided.
+- Concerning Ocaml, extracted code is now ensured to always type-check,
+ thanks to automatic inserting of Obj.magic.
+- Experimental extraction of Coq new modules to Ocaml modules.
+
+Proof rendering in natural language
+
+- Export of theories to XML for publishing and rendering purposes now
+ includes proof-trees (see http://www.cs.unibo.it/helm)
+
+Miscellaneous
+
+- Printing Coercion now used through the standard keywords Set/Add, Test, Print
+- "Print Term id" is an alias for "Print id"
+- New switch "Unset/Set Printing Symbols" to control printing of
+ symbolic notations
+- Two new variants of implicit arguments are available
+ - "Unset/Set Contextual Implicits" tells to consider implicit also the
+ arguments inferable from the context (e.g. for nil or refl_eq)
+ - "Unset/Set Strict Implicits" tells to consider implicit only the
+ arguments that are inferable in any case (i.e. arguments that occurs
+ as argument of rigid constants in the type of the remaining arguments;
+ e.g. the witness of an existential is not strict since it can vanish when
+ applied to a predicate which does not use its argument)
+
+Incompatibilities
+
+- "Grammar tactic ... : ast" and "Grammar vernac ... : ast" are no
+ longer supported, use TACTIC EXTEND and VERNAC COMMAND EXTEND on the
+ ML-side instead
+- Transparency of le_lt_dec and co (leads to some simplification in
+ proofs; in some cases, incompatibilites is solved by declaring locally
+ opaque the relevant constant)
+- Opaque Local do not now survive section closing (rename them into
+ Remark/Lemma/... to get them still surviving the sections; this
+ renaming allows also to solve incompatibilites related to now
+ forbidden calls to the tactic Clear)
+- Remark and Fact have no longer (very) long names (use Local instead in case
+ of name conflict)
+
+Bugs
+
+- Improved localisation of errors in Syntactic Definitions
+- Induction principle creation failure in presence of let-in fixed (#1459)
+- Inversion bugs fixed (#1427 and #1437)
+- Omega bug related to Set fixed (#1384)
+- Type-checking inefficiency of nested destructuring let-in fixed (#1435)
+- Improved handling of let-in during holes resolution phase (#1460)
+
+Efficiency
+
+- Implementation of a memory sharing strategy reducing memory
+ requirements by an average ratio of 3.
+
+Changes from V7.3 to V7.3.1
+===========================
+
+Bug fixes
+
+ - Corrupted Field tactic and Match Context tactic construction fixed
+ - Checking of names already existing in Assert added (#1386)
+ - Invalid argument bug in Exact tactic solved (#1387)
+ - Colliding bound names bug fixed (#1412)
+ - Wrong non-recursivity test for Record fixed (#1394)
+ - Out of memory/seg fault bug related to parametric inductive fixed (#1404)
+ - Setoid_replace/Setoid_rewrite bug wrt "==" fixed
+
+Misc
+
+ - Ocaml version >= 3.06 is needed to compile Coq from sources
+ - Simplification of fresh names creation strategy for Assert, Pose and
+ LetTac (#1402)
+
+Changes from V7.2 to V7.3
+=========================
+
+Language
+
+- Slightly improved compilation of pattern-matching (slight source of
+ incompatibilities)
+- Record's now accept anonymous fields "_" which does not build projections
+- Changes in the allowed elimination sorts for certain class of inductive
+ definitions : an inductive definition without constructors
+ of Sort Prop can be eliminated on sorts Set and Type A "singleton"
+ inductive definition (one constructor with arguments in the sort Prop
+ like conjunction of two propositions or equality) can be eliminated
+ directly on sort Type (In V7.2, only the sorts Prop and Set were allowed)
+
+Tactics
+
+- New tactic "Rename x into y" for renaming hypotheses
+- New tactics "Pose x:=u" and "Pose u" to add definitions to local context
+- Pattern now working on partially applied subterms
+- Ring no longer applies irreversible congruence laws of mult but
+ better applies congruence laws of plus (slight source of incompatibilities).
+- Field now accepts terms to be simplified as arguments (as for Ring). This
+ extension has been also implemented using the toplevel tactic language.
+- Intuition does no longer unfold constants except "<->" and "~". It
+ can be parameterized by a tactic. It also can introduce dependent
+ product if needed (source of incompatibilities)
+- "Match Context" now matching more recent hypotheses first and failing only
+ on user errors and Fail tactic (possible source of incompatibilities)
+- Tactic Definition's without arguments now allowed in Coq states
+- Better simplification and discrimination made by Inversion (source
+ of incompatibilities)
+
+Bugs
+
+- "Intros H" now working like "Intro H" trying first to reduce if not a product
+- Forward dependencies in Cases now taken into account
+- Known bugs related to Inversion and let-in's fixed
+- Bug unexpected Delta with let-in now fixed
+
+Extraction (details in plugins/extraction/CHANGES or documentation)
+
+- Signatures of extracted terms are now mostly expunged from dummy arguments.
+- Haskell extraction is now operational (tested & debugged).
+
+Standard library
+
+- Some additions in [ZArith]: three files (Zcomplements.v, Zpower.v
+ and Zlogarithms.v) moved from plugins/omega in order to be more
+ visible, one Zsgn function, more induction principles (Wf_Z.v and
+ tail of Zcomplements.v), one more general Euclid theorem
+- Peano_dec.v and Compare_dec.v now part of Arith.v
+
+Tools
+
+- new option -dump-glob to coqtop to dump globalizations (to be used by the
+ new documentation tool coqdoc; see http://www.lri.fr/~filliatr/coqdoc)
+
+User Contributions
+
+- CongruenceClosure (congruence closure decision procedure)
+ [Pierre Corbineau, ENS Cachan]
+- MapleMode (an interface to embed Maple simplification procedures over
+ rational fractions in Coq)
+ [David Delahaye, Micaela Mayero, Chalmers University]
+- Presburger: A formalization of Presburger's algorithm
+ [Laurent Thery, INRIA Sophia Antipolis]
+- Chinese has been rewritten using Z from ZArith as datatype
+ ZChinese is the new version, Chinese the obsolete one
+ [Pierre Letouzey, LRI Orsay]
+
+Incompatibilities
+
+- Ring: exceptional incompatibilities (1 above 650 in submitted user
+ contribs, leading to a simplification)
+- Intuition: does not unfold any definition except "<->" and "~"
+- Cases: removal of some extra Cases in configurations of the form
+ "Cases ... of C _ => ... | _ D => ..." (effects on 2 definitions of
+ submitted user contributions necessitating the removal of now superfluous
+ proof steps in 3 different proofs)
+- Match Context, in case of incompatibilities because of a now non
+ trapped error (e.g. Not_found or Failure), use instead tactic Fail
+ to force Match Context trying the next clause
+- Inversion: better simplification and discrimination may occasionally
+ lead to less subgoals and/or hypotheses and different naming of hypotheses
+- Unification done by Apply/Elim has been changed and may exceptionally lead
+ to incompatible instantiations
+- Peano_dec.v and Compare_dec.v parts of Arith.v make Auto more
+ powerful if these files were not already required (1 occurrence of
+ this in submitted user contribs)
+
+Changes from V7.1 to V7.2
+=========================
+
+Language
+
+- Automatic insertion of patterns for local definitions in the type of
+ the constructors of an inductive types (for compatibility with V6.3
+ let-in style)
+- Coercions allowed in Cases patterns
+- New declaration "Canonical Structure id = t : I" to help resolution of
+ equations of the form (proj ?)=a; if proj(e)=a then a is canonically
+ equipped with the remaining fields in e, i.e. ? is instantiated by e
+
+Tactics
+
+- New tactic "ClearBody H" to clear the body of definitions in local context
+- New tactic "Assert H := c" for forward reasoning
+- Slight improvement in naming strategy for NewInduction/NewDestruct
+- Intuition/Tauto do not perform useless unfolding and work up to conversion
+
+Extraction (details in plugins/extraction/CHANGES or documentation)
+
+- Syntax changes: there are no more options inside the extraction commands.
+ New commands for customization and options have been introduced instead.
+- More optimizations on extracted code.
+- Extraction tests are now embedded in 14 user contributions.
+
+Standard library
+
+- In [Relations], Rstar.v and Newman.v now axiom-free.
+- In [Sets], Integers.v now based on nat
+- In [Arith], more lemmas in Min.v, new file Max.v, tail-recursive
+ plus and mult added to Plus.v and Mult.v respectively
+- New directory [Sorting] with a proof of heapsort (dragged from 6.3.1 lib)
+- In [Reals], more lemmas in Rbase.v, new lemmas on square, square root and
+ trigonometric functions (R_sqr.v - Rtrigo.v); a complementary approach
+ and new theorems about continuity and derivability in Ranalysis.v; some
+ properties in plane geometry such as translation, rotation or similarity
+ in Rgeom.v; finite sums and Chasles property in Rsigma.v
+
+Bugs
+
+- Confusion between implicit args of locals and globals of same base name fixed
+- Various incompatibilities wrt inference of "?" in V6.3.1 fixed
+- Implicits in infix section variables bug fixed
+- Known coercions bugs fixed
+
+- Apply "universe anomaly" bug fixed
+- NatRing now working
+- "Discriminate 1", "Injection 1", "Simplify_eq 1" now working
+- NewInduction bugs with let-in and recursively dependent hypotheses fixed
+- Syntax [x:=t:T]u now allowed as mentioned in documentation
+
+- Bug with recursive inductive types involving let-in fixed
+- Known pattern-matching bugs fixed
+- Known Cases elimination predicate bugs fixed
+- Improved errors messages for pattern-matching and projections
+- Better error messages for ill-typed Cases expressions
+
+Incompatibilities
+
+- New naming strategy for NewInduction/NewDestruct may affect 7.1 compatibility
+- Extra parentheses may exceptionally be needed in tactic definitions.
+- Coq extensions written in Ocaml need to be updated (see dev/changements.txt
+ for a description of the main changes in the interface files of V7.2)
+- New behaviour of Intuition/Tauto may exceptionally lead to incompatibilities
+
+----------------------------------------------------------------------------
+Changes from V6.3.1 and V7.0 to V7.1
+====================================
+
+Notes:
+
+- items followed by (**) are important sources of incompatibilities
+- items followed by (*) may exceptionally be sources of incompatibilities
+- items followed by (+) have been introduced in version 7.0
+
+
+Main novelties
+==============
+
+References are to Coq V7.1 reference manual
+
+- New primitive let-in construct (see sections 1.2.8 and )
+- Long names (see sections 2.6 and 2.7)
+- New high-level tactic language (see chapter 10)
+- Improved search facilities (see section 5.2)
+- New extraction algorithm managing the Type level (see chapter 17)
+- New rewriting tactic for arbitrary equalities (see chapter 19)
+- New tactic Field to decide equalities on commutative fields (see 7.11)
+- New tactic Fourier to solve linear inequalities on reals numbers (see 7.11)
+- New tactics for induction/case analysis in "natural" style (see 7.7)
+- Deep restructuration of the code (safer, simpler and more efficient)
+- Export of theories to XML for publishing and rendering purposes
+ (see http://www.cs.unibo.it/helm)
+
+
+Details of changes
+==================
+
+Language: new "let-in" construction
+-----------------------------------
+
+- New construction for local definitions (let-in) with syntax [x:=u]t (*)(+)
+
+- Local definitions allowed in Record (a.k.a. record à la Randy Pollack)
+
+
+Language: long names
+--------------------
+
+- Each construction has a unique absolute names built from a base
+ name, the name of the module in which they are defined (Top if in
+ coqtop), and possibly an arbitrary long sequence of directory (e.g.
+ "Coq.Lists.PolyList.flat_map" where "Coq" means that "flat_map" is part
+ of Coq standard library, "Lists" means it is defined in the Lists
+ library and "PolyList" means it is in the file Polylist) (+)
+
+- Constructions can be referred by their base name, or, in case of
+ conflict, by a "qualified" name, where the base name is prefixed
+ by the module name (and possibly by a directory name, and so
+ on). A fully qualified name is an absolute name which always refer
+ to the construction it denotes (to preserve the visibility of
+ all constructions, no conflict is allowed for an absolute name) (+)
+
+- Long names are available for modules with the possibility of using
+ the directory name as a component of the module full name (with
+ option -R to coqtop and coqc, or command Add LoadPath) (+)
+
+- Improved conflict resolution strategy (the Unix PATH model),
+ allowing more constructions to be referred just by their base name
+
+
+Language: miscellaneous
+-----------------------
+
+- The names of variables for Record projections _and_ for induction principles
+ (e.g. sum_ind) is now based on the first letter of their type (main
+ source of incompatibility) (**)(+)
+
+- Most typing errors have now a precise location in the source (+)
+
+- Slightly different mechanism to solve "?" (*)(+)
+
+- More arguments may be considered implicit at section closing (*)(+)
+
+- Bug with identifiers ended by a number greater than 2^30 fixed (+)
+
+- New visibility discipline for Remark, Fact and Local: Remark's and
+ Fact's now survive at the end of section, but are only accessible using a
+ qualified names as soon as their strength expires; Local's disappear and
+ are moved into local definitions for each construction persistent at
+ section closing
+
+
+Language: Cases
+---------------
+
+- Cases no longer considers aliases inferable from dependencies in types (*)(+)
+
+- A redundant clause in Cases is now an error (*)
+
+
+Reduction
+---------
+
+- New reduction flags "Zeta" and "Evar" in Eval Compute, for inlining of
+ local definitions and instantiation of existential variables
+
+- Delta reduction flag does not perform Zeta and Evar reduction any more (*)
+
+- Constants declared as opaque (using Qed) can no longer become
+ transparent (a constant intended to be alternatively opaque and
+ transparent must be declared as transparent (using Defined)); a risk
+ exists (until next Coq version) that Simpl and Hnf reduces opaque
+ constants (*)
+
+
+New tactics
+-----------
+
+- New set of tactics to deal with types equipped with specific
+ equalities (a.k.a. Setoids, e.g. nat equipped with eq_nat) [by C. Renard]
+
+- New tactic Assert, similar to Cut but expected to be more user-friendly
+
+- New tactic NewDestruct and NewInduction intended to replace Elim
+ and Induction, Case and Destruct in a more user-friendly way (see
+ restrictions in the reference manual)
+
+- New tactic ROmega: an experimental alternative (based on reflexion) to Omega
+ [by P. Crégut]
+
+- New tactic language Ltac (see reference manual) (+)
+
+- New versions of Tauto and Intuition, fully rewritten in the new Ltac
+ language; they run faster and produce more compact proofs; Tauto is
+ fully compatible but, in exchange of a better uniformity, Intuition
+ is slightly weaker (then use Tauto instead) (**)(+)
+
+- New tactic Field to decide equalities on commutative fields (as a
+ special case, it works on real numbers) (+)
+
+- New tactic Fourier to solve linear inequalities on reals numbers
+ [by L. Pottier] (+)
+
+- New tactics dedicated to real numbers: DiscrR, SplitRmult, SplitAbsolu (+)
+
+
+Changes in existing tactics
+---------------------------
+
+- Reduction tactics in local definitions apply only to the body
+
+- New syntax of the form "Compute in Type of H." to require a reduction on
+ the types of local definitions
+
+- Inversion, Injection, Discriminate, ... apply also on the
+ quantified premises of a goal (using the "Intros until" syntax)
+
+- Decompose has been fixed but hypotheses may get different names (*)(+)
+
+- Tauto now manages uniformly hypotheses and conclusions of the form
+ "t=t" which all are considered equivalent to "True". Especially,
+ Tauto now solves goals of the form "H : ~ t = t |- A".
+
+- The "Let" tactic has been renamed "LetTac" and is now based on the
+ primitive "let-in" (+)
+
+- Elim can no longer be used with an elimination schema different from
+ the one defined at definition time of the inductive type. To overload
+ an elimination schema, use "Elim <hyp> using <name of the new schema>"
+ (*)(+)
+
+- Simpl no longer unfolds the recursive calls of a mutually defined
+ fixpoint (*)(+)
+
+- Intro now fails if the hypothesis name already exists (*)(+)
+
+- "Require Prolog" is no longer needed (i.e. it is available by default) (*)(+)
+
+- Unfold now fails on a non unfoldable identifier (*)(+)
+
+- Unfold also applies on definitions of the local context
+
+- AutoRewrite now deals only with the main goal and it is the purpose of
+ Hint Rewrite to deal with generated subgoals (+)
+
+- Redundant or incompatible instantiations in Apply ... with ... are now
+ correctly managed (+)
+
+
+Efficiency
+----------
+
+- Excessive memory uses specific to V7.0 fixed
+
+- Sizes of .vo files vary a lot compared to V6.3 (from -30% to +300%
+ depending on the developments)
+
+- An improved reduction strategy for lazy evaluation
+
+- A more economical mechanism to ensure logical consistency at the Type level;
+ warning: this is experimental and may produce "universes" anomalies
+ (please report)
+
+
+Concrete syntax of constructions
+--------------------------------
+
+- Only identifiers starting with "_" or a letter, and followed by letters,
+ digits, "_" or "'" are allowed (e.g. "$" and "@" are no longer allowed) (*)
+
+- A multiple binder like (a:A)(a,b:(P a))(Q a) is no longer parsed as
+ (a:A)(a0:(P a))(b:(P a))(Q a0) but as (a:A)(a0:(P a))(b:(P a0))(Q a0) (*)(+)
+
+- A dedicated syntax has been introduced for Reals (e.g ``3+1/x``) (+)
+
+- Pretty-printing of Infix notations fixed. (+)
+
+
+Parsing and grammar extension
+-----------------------------
+
+- More constraints when writing ast
+
+ - "{...}" and the macros $LIST, $VAR, etc. now expect a metavariable
+ (an identifier starting with $) (*)
+ - identifiers should starts with a letter or "_" and be followed
+ by letters, digits, "_" or "'" (other characters are still
+ supported but it is not advised to use them) (*)(+)
+
+- Entry "command" in "Grammar" and quotations (<<...>> stuff) is
+ renamed "constr" as in "Syntax" (+)
+
+- New syntax "[" sentence_1 ... sentence_n"]." to group sentences (useful
+ for Time and to write grammar rules abbreviating several commands) (+)
+
+- The default parser for actions in the grammar rules (and for
+ patterns in the pretty-printing rules) is now the one associated to
+ the grammar (i.e. vernac, tactic or constr); no need then for
+ quotations as in <:vernac:<...>>; to return an "ast", the grammar
+ must be explicitly typed with tag ": ast" or ": ast list", or if a
+ syntax rule, by using <<...>> in the patterns (expression inside
+ these angle brackets are parsed as "ast"); for grammars other than
+ vernac, tactic or constr, you may explicitly type the action with
+ tags ": constr", ": tactic", or ":vernac" (**)(+)
+
+- Interpretation of names in Grammar rule is now based on long names,
+ which allows to avoid problems (or sometimes tricks;) related to
+ overloaded names (+)
+
+
+New commands
+------------
+
+- New commands "Print XML All", "Show XML Proof", ... to show or
+ export theories to XML to be used with Helm's publishing and rendering
+ tools (see http://www.cs.unibo.it/helm) (by Claudio Sacerdoti Coen) (+)
+
+- New commands to manually set implicit arguments (+)
+
+ - "Implicits ident." to activate the implicit arguments mode just for ident
+ - "Implicits ident [num1 num2 ...]." to explicitly give which
+ arguments have to be considered as implicit
+
+- New SearchPattern/SearchRewrite (by Yves Bertot) (+)
+
+- New commands "Debug on"/"Debug off" to activate/deactivate the tactic
+ language debugger (+)
+
+- New commands to map physical paths to logical paths (+)
+ - Add LoadPath physical_dir as logical_dir
+ - Add Rec LoadPath physical_dir as logical_dir
+
+
+Changes in existing commands
+----------------------------
+
+- Generalization of the usage of qualified identifiers in tactics
+ and commands about globals, e.g. Decompose, Eval Delta;
+ Hints Unfold, Transparent, Require
+
+- Require synchronous with Reset; Require's scope stops at Section ending (*)
+
+- For a module indirectly loaded by a "Require" but not exported,
+ the command "Import module" turns the constructions defined in the
+ module accessible by their short name, and activates the Grammar,
+ Syntax, Hint, ... declared in the module (+)
+
+- The scope of the "Search" command can be restricted to some modules (+)
+
+- Final dot in command (full stop/period) must be followed by a blank
+ (newline, tabulation or whitespace) (+)
+
+- Slight restriction of the syntax for Cbv Delta: if present, option [-myconst]
+ must immediately follow the Delta keyword (*)(+)
+
+- SearchIsos currently not supported
+
+- Add ML Path is now implied by Add LoadPath (+)
+
+- New names for the following commands (+)
+
+ AddPath -> Add LoadPath
+ Print LoadPath -> Print LoadPath
+ DelPath -> Remove LoadPath
+ AddRecPath -> Add Rec LoadPath
+ Print Path -> Print Coercion Paths
+
+ Implicit Arguments On -> Set Implicit Arguments
+ Implicit Arguments Off -> Unset Implicit Arguments
+
+ Begin Silent -> Set Silent
+ End Silent -> Unset Silent.
+
+
+Tools
+-----
+
+- coqtop (+)
+
+ - Two executables: coqtop.byte and coqtop.opt (if supported by the platform)
+ - coqtop is a link to the more efficient executable (coqtop.opt if present)
+ - option -full is obsolete (+)
+
+- do_Makefile renamed into coq_makefile (+)
+
+- New option -R to coqtop and coqc to map a physical directory to a logical
+ one (+)
+
+- coqc no longer needs to create a temporary file
+
+- No more warning if no initialization file .coqrc exists
+
+
+Extraction
+----------
+
+- New algorithm for extraction able to deal with "Type" (+)
+ (by J.-C. Filliâtre and P. Letouzey)
+
+
+Standard library
+----------------
+
+- New library on maps on integers (IntMap, contributed by Jean Goubault)
+
+- New lemmas about integer numbers [ZArith]
+
+- New lemmas and a "natural" syntax for reals [Reals] (+)
+
+- Exc/Error/Value renamed into Option/Some/None (*)
+
+
+New user contributions
+----------------------
+
+- Constructive complex analysis and the Fundamental Theorem of Algebra [FTA]
+ (Herman Geuvers, Freek Wiedijk, Jan Zwanenburg, Randy Pollack,
+ Henk Barendregt, Nijmegen)
+
+- A new axiomatization of ZFC set theory [Functions_in_ZFC]
+ (C. Simpson, Sophia-Antipolis)
+
+- Basic notions of graph theory [GRAPHS-BASICS] (Jean Duprat, Lyon)
+
+- A library for floating-point numbers [Float] (Laurent Théry, Sylvie Boldo,
+ Sophia-Antipolis)
+
+- Formalisation of CTL and TCTL temporal logic [CtlTctl] (Carlos
+ Daniel Luna,Montevideo)
+
+- Specification and verification of the Railroad Crossing Problem
+ in CTL and TCTL [RailroadCrossing] (Carlos Daniel Luna,Montevideo)
+
+- P-automaton and the ABR algorithm [PAutomata]
+ (Christine Paulin, Emmanuel Freund, Orsay)
+
+- Semantics of a subset of the C language [MiniC]
+ (Eduardo Giménez, Emmanuel Ledinot, Suresnes)
+
+- Correctness proofs of the following imperative algorithms:
+ Bresenham line drawing algorithm [Bresenham], Marché's minimal edition
+ distance algorithm [Diff] (Jean-Christophe Filliâtre, Orsay)
+
+- Correctness proofs of Buchberger's algorithm [Buchberger] and RSA
+ cryptographic algorithm [Rsa] (Laurent Théry, Sophia-Antipolis)
+
+- Correctness proof of Stalmarck tautology checker algorithm
+ [Stalmarck] (Laurent Théry, Pierre Letouzey, Sophia-Antipolis)