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diff --git a/CHANGES b/CHANGES new file mode 100644 index 00000000..2daeded1 --- /dev/null +++ b/CHANGES @@ -0,0 +1,1027 @@ +Changes from V8.0 to V8.0pl1 +============================ + +Unicode support + +- Miscellaneous Mathematical Symbols-A and B, and Supplemental + Arrows-A now supported + +Bug fixes + +- GPL-incompatible QPL files for CoqIde are now GPL +- Pretty-printing of coercions to Funclass fixed and improved +- Erroneous interpretation of the quantified hypothesis in intro until fixed +- See coq-bugs web page for a full list of fixed bugs (look for + fixes in V8-0-bugfix before July 17) + +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 + (TODO : doc). +- "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 + +- UTF-8 encoded unicode blocks 0380-03FF (greek letters) and 2100-214F + (letter-like, including aleph and double N,Z,Q,R) are supported + identifiers; UTF-8 unicode blocs 2200-22FF (mathematical operators), + 2A00-2AFF (supplemental mathematical operators) 2300-23FF + (miscellaneous technical, including sqrt symbol), 2600-26FF + (miscellaneous symbols) 2190-21FF (arrows A) and 2900-297F (arrows B) + are supported 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 contrib/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 developped 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 contrib/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 (#238) +- Inversion bugs fixed (#212 and #220) +- Omega bug related to Set fixed (#180) +- Type-checking inefficiency of nested destructuring let-in fixed (#216) +- Improved handling of let-in during holes resolution phase (#239) + +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 (PR#182) + - Invalid argument bug in Exact tactic solved (PR#183) + - Colliding bound names bug fixed (PR#202) + - Wrong non-recursivity test for Record fixed (PR#189) + - Out of memory/seg fault bug related to parametric inductive fixed (PR#195) + - 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 (PR#192) + +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 contrib/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 contrib/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 contrib/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) |