diff options
Diffstat (limited to 'doc/sphinx/proof-engine/vernacular-commands.rst')
| -rw-r--r-- | doc/sphinx/proof-engine/vernacular-commands.rst | 1224 |
1 files changed, 1224 insertions, 0 deletions
diff --git a/doc/sphinx/proof-engine/vernacular-commands.rst b/doc/sphinx/proof-engine/vernacular-commands.rst new file mode 100644 index 000000000..3ba0607c5 --- /dev/null +++ b/doc/sphinx/proof-engine/vernacular-commands.rst @@ -0,0 +1,1224 @@ +\chapter[Vernacular commands]{Vernacular commands\label{Vernacular-commands} +\label{Other-commands}} +%HEVEA\cutname{vernacular.html} + +\section{Displaying} + +\subsection[\tt Print {\qualid}.]{\tt Print {\qualid}.\comindex{Print}} +This command displays on the screen information about the declared or +defined object referred by {\qualid}. + +\begin{ErrMsgs} +\item {\qualid} \errindex{not a defined object} +\item \errindex{Universe instance should have length} $n$. +\item \errindex{This object does not support universe names.} +\end{ErrMsgs} + +\begin{Variants} +\item {\tt Print Term {\qualid}.} +\comindex{Print Term}\\ +This is a synonym to {\tt Print {\qualid}} when {\qualid} denotes a +global constant. + +\item {\tt About {\qualid}.} +\label{About} +\comindex{About}\\ +This displays various information about the object denoted by {\qualid}: +its kind (module, constant, assumption, inductive, +constructor, abbreviation, \ldots), long name, type, implicit +arguments and argument scopes. It does not print the body of +definitions or proofs. + +\item {\tt Print {\qualid}@\{names\}.}\\ +This locally renames the polymorphic universes of {\qualid}. +An underscore means the raw universe is printed. +This form can be used with {\tt Print Term} and {\tt About}. + +%\item {\tt Print Proof {\qualid}.}\comindex{Print Proof}\\ +%In case \qualid\ denotes an opaque theorem defined in a section, +%it is stored on a special unprintable form and displayed as +%{\tt <recipe>}. {\tt Print Proof} forces the printable form of \qualid\ +%to be computed and displays it. +\end{Variants} + +\subsection[\tt Print All.]{\tt Print All.\comindex{Print All}} +This command displays information about the current state of the +environment, including sections and modules. + +\begin{Variants} +\item {\tt Inspect \num.}\comindex{Inspect}\\ +This command displays the {\num} last objects of the current +environment, including sections and modules. +\item {\tt Print Section {\ident}.}\comindex{Print Section}\\ +should correspond to a currently open section, this command +displays the objects defined since the beginning of this section. +% Discontinued +%% \item {\tt Print.}\comindex{Print}\\ +%% This command displays the axioms and variables declarations in the +%% environment as well as the constants defined since the last variable +%% was introduced. +\end{Variants} + +\section{Flags, Options and Tables} + +{\Coq} configurability is based on flags (e.g. {\tt Set Printing All} in +Section~\ref{SetPrintingAll}), options (e.g. {\tt Set Printing Width + {\integer}} in Section~\ref{SetPrintingWidth}), or tables (e.g. {\tt + Add Printing Record {\ident}}, in Section~\ref{AddPrintingLet}). The +names of flags, options and tables are made of non-empty sequences of +identifiers (conventionally with capital initial letter). The general +commands handling flags, options and tables are given below. + +\subsection[\tt Set {\rm\sl flag}.]{\tt Set {\rm\sl flag}.\comindex{Set}} +This command switches {\rm\sl flag} on. The original state of +{\rm\sl flag} is restored when the current module ends. + +\begin{Variants} +\item {\tt Local Set {\rm\sl flag}.}\\ +This command switches {\rm\sl flag} on. The original state of +{\rm\sl flag} is restored when the current \emph{section} ends. +\item {\tt Global Set {\rm\sl flag}.}\\ +This command switches {\rm\sl flag} on. The original state of +{\rm\sl flag} is \emph{not} restored at the end of the module. Additionally, +if set in a file, {\rm\sl flag} is switched on when the file is +{\tt Require}-d. +\end{Variants} + +\subsection[\tt Unset {\rm\sl flag}.]{\tt Unset {\rm\sl flag}.\comindex{Unset}} +This command switches {\rm\sl flag} off. The original state of {\rm\sl flag} +is restored when the current module ends. + +\begin{Variants} +\item {\tt Local Unset {\rm\sl flag}.\comindex{Local Unset}}\\ +This command switches {\rm\sl flag} off. The original state of {\rm\sl flag} +is restored when the current \emph{section} ends. +\item {\tt Global Unset {\rm\sl flag}.\comindex{Global Unset}}\\ +This command switches {\rm\sl flag} off. The original state of +{\rm\sl flag} is \emph{not} restored at the end of the module. Additionally, +if set in a file, {\rm\sl flag} is switched off when the file is +{\tt Require}-d. +\end{Variants} + +\subsection[\tt Test {\rm\sl flag}.]{\tt Test {\rm\sl flag}.\comindex{Test}} +This command prints whether {\rm\sl flag} is on or off. + +\subsection[\tt Set {\rm\sl option} {\rm\sl value}.]{\tt Set {\rm\sl option} {\rm\sl value}.\comindex{Set}} +This command sets {\rm\sl option} to {\rm\sl value}. The original value of +{\rm\sl option} is restored when the current module ends. + +\begin{Variants} +\item {\tt Local Set {\rm\sl option} {\rm\sl value}.\comindex{Local Set}} +This command sets {\rm\sl option} to {\rm\sl value}. The original value of +{\rm\sl option} is restored at the end of the module. +\item {\tt Global Set {\rm\sl option} {\rm\sl value}.\comindex{Global Set}} +This command sets {\rm\sl option} to {\rm\sl value}. The original value of +{\rm\sl option} is \emph{not} restored at the end of the module. Additionally, +if set in a file, {\rm\sl option} is set to {\rm\sl value} when the file is +{\tt Require}-d. +\end{Variants} + +\subsection[\tt Unset {\rm\sl option}.]{\tt Unset {\rm\sl option}.\comindex{Unset}} +This command resets {\rm\sl option} to its default value. + +\begin{Variants} +\item {\tt Local Unset {\rm\sl option}.\comindex{Local Unset}}\\ +This command resets {\rm\sl option} to its default value. The original state of {\rm\sl option} +is restored when the current \emph{section} ends. +\item {\tt Global Unset {\rm\sl option}.\comindex{Global Unset}}\\ +This command resets {\rm\sl option} to its default value. The original state of +{\rm\sl option} is \emph{not} restored at the end of the module. Additionally, +if unset in a file, {\rm\sl option} is reset to its default value when the file is +{\tt Require}-d. +\end{Variants} + +\subsection[\tt Test {\rm\sl option}.]{\tt Test {\rm\sl option}.\comindex{Test}} +This command prints the current value of {\rm\sl option}. + +\subsection{Tables} +The general commands for tables are {\tt Add {\rm\sf table} {\rm\sl + value}}, {\tt Remove {\rm\sf table} {\rm\sl value}}, {\tt Test + {\rm\sf table}}, {\tt Test {\rm\sf table} for {\rm\sl value}} and + {\tt Print Table {\rm\sf table}}. + +\subsection[\tt Print Options.]{\tt Print Options.\comindex{Print Options}} +This command lists all available flags, options and tables. + +\begin{Variants} +\item {\tt Print Tables}.\comindex{Print Tables}\\ +This is a synonymous of {\tt Print Options.} +\end{Variants} + +\section{Requests to the environment} + +\subsection[\tt Check {\term}.]{\tt Check {\term}.\label{Check} +\comindex{Check}} +This command displays the type of {\term}. When called in proof mode, +the term is checked in the local context of the current subgoal. + +\begin{Variants} +\item {\tt selector: Check {\term}}.\\ +specifies on which subgoal to perform typing (see + Section~\ref{tactic-syntax}). +\end{Variants} + + +\subsection[\tt Eval {\rm\sl convtactic} in {\term}.]{\tt Eval {\rm\sl convtactic} in {\term}.\comindex{Eval}} + +This command performs the specified reduction on {\term}, and displays +the resulting term with its type. The term to be reduced may depend on +hypothesis introduced in the first subgoal (if a proof is in +progress). + +\SeeAlso Section~\ref{Conversion-tactics}. + +\subsection[\tt Compute {\term}.]{\tt Compute {\term}.\comindex{Compute}} + +This command performs a call-by-value evaluation of {\term} by using +the bytecode-based virtual machine. It is a shortcut for +{\tt Eval vm\_compute in {\term}}. + +\SeeAlso Section~\ref{Conversion-tactics}. + +\subsection[\tt Extraction \term.]{\tt Extraction \term.\label{ExtractionTerm} +\comindex{Extraction}} +This command displays the extracted term from +{\term}. The extraction is processed according to the distinction +between {\Set} and {\Prop}; that is to say, between logical and +computational content (see Section~\ref{Sorts}). The extracted term is +displayed in {\ocaml} syntax, where global identifiers are still +displayed as in \Coq\ terms. + +\begin{Variants} +\item \texttt{Recursive Extraction} {\qualid$_1$} \ldots{} {\qualid$_n$}{\tt .}\\ + Recursively extracts all the material needed for the extraction of + global {\qualid$_1$}, \ldots, {\qualid$_n$}. +\end{Variants} + +\SeeAlso Chapter~\ref{Extraction}. + +\subsection[\tt Print Assumptions {\qualid}.]{\tt Print Assumptions {\qualid}.\comindex{Print Assumptions}} +\label{PrintAssumptions} + +This commands display all the assumptions (axioms, parameters and +variables) a theorem or definition depends on. Especially, it informs +on the assumptions with respect to which the validity of a theorem +relies. + +\begin{Variants} +\item \texttt{\tt Print Opaque Dependencies {\qualid}. + \comindex{Print Opaque Dependencies}}\\ + Displays the set of opaque constants {\qualid} relies on in addition + to the assumptions. +\item \texttt{\tt Print Transparent Dependencies {\qualid}. + \comindex{Print Transparent Dependencies}}\\ + Displays the set of transparent constants {\qualid} relies on in addition + to the assumptions. +\item \texttt{\tt Print All Dependencies {\qualid}. + \comindex{Print All Dependencies}}\\ + Displays all assumptions and constants {\qualid} relies on. +\end{Variants} + +\subsection[\tt Search {\qualid}.]{\tt Search {\qualid}.\comindex{Search}} +This command displays the name and type of all objects (hypothesis of +the current goal, theorems, axioms, etc) of the current context whose +statement contains \qualid. This command is useful to remind the user +of the name of library lemmas. + +\begin{ErrMsgs} +\item \errindex{The reference \qualid\ was not found in the current +environment}\\ + There is no constant in the environment named \qualid. +\end{ErrMsgs} + +\newcommand{\termpatternorstr}{{\termpattern}\textrm{\textsl{-}}{\str}} + +\begin{Variants} +\item {\tt Search {\str}.} + +If {\str} is a valid identifier, this command displays the name and type +of all objects (theorems, axioms, etc) of the current context whose +name contains {\str}. If {\str} is a notation's string denoting some +reference {\qualid} (referred to by its main symbol as in \verb="+"= +or by its notation's string as in \verb="_ + _"= or \verb="_ 'U' _"=, see +Section~\ref{Notation}), the command works like {\tt Search +{\qualid}}. + +\item {\tt Search {\str}\%{\delimkey}.} + +The string {\str} must be a notation or the main symbol of a notation +which is then interpreted in the scope bound to the delimiting key +{\delimkey} (see Section~\ref{scopechange}). + +\item {\tt Search {\termpattern}.} + +This searches for all statements or types of definition that contains +a subterm that matches the pattern {\termpattern} (holes of the +pattern are either denoted by ``{\texttt \_}'' or +by ``{\texttt ?{\ident}}'' when non linear patterns are expected). + +\item {\tt Search \nelist{\zeroone{-}{\termpatternorstr}}{}.}\\ + +\noindent where {\termpatternorstr} is a +{\termpattern} or a {\str}, or a {\str} followed by a scope +delimiting key {\tt \%{\delimkey}}. + +This generalization of {\tt Search} searches for all objects +whose statement or type contains a subterm matching {\termpattern} (or +{\qualid} if {\str} is the notation for a reference {\qualid}) and +whose name contains all {\str} of the request that correspond to valid +identifiers. If a {\termpattern} or a {\str} is prefixed by ``-'', the +search excludes the objects that mention that {\termpattern} or that +{\str}. + +\item + {\tt Search} \nelist{{\termpatternorstr}}{} + {\tt inside} {\module$_1$} \ldots{} {\module$_n$}{\tt .} + +This restricts the search to constructions defined in modules +{\module$_1$} \ldots{} {\module$_n$}. + +\item + {\tt Search \nelist{{\termpatternorstr}}{} + outside {\module$_1$}...{\module$_n$}.} + +This restricts the search to constructions not defined in modules +{\module$_1$} \ldots{} {\module$_n$}. + +\item {\tt selector: Search \nelist{\zeroone{-}{\termpatternorstr}}{}.} + + This specifies the goal on which to search hypothesis (see + Section~\ref{tactic-syntax}). By default the 1st goal is searched. + This variant can be combined with other variants presented here. +\end{Variants} + +\examples + +\begin{coq_example*} +Require Import ZArith. +\end{coq_example*} +\begin{coq_example} +Search Z.mul Z.add "distr". +Search "+"%Z "*"%Z "distr" -positive -Prop. +Search (?x * _ + ?x * _)%Z outside OmegaLemmas. +\end{coq_example} + +\Warning \comindex{SearchAbout} Up to {\Coq} version 8.4, {\tt Search} +had the behavior of current {\tt SearchHead} and the behavior of +current {\tt Search} was obtained with command {\tt SearchAbout}. For +compatibility, the deprecated name {\tt SearchAbout} can still be used +as a synonym of {\tt Search}. For compatibility, the list of objects to +search when using {\tt SearchAbout} may also be enclosed by optional +{\tt [ ]} delimiters. + +\subsection[\tt SearchHead {\term}.]{\tt SearchHead {\term}.\comindex{SearchHead}} +This command displays the name and type of all hypothesis of the +current goal (if any) and theorems of the current context whose +statement's conclusion has the form {\tt ({\term} t1 .. + tn)}. This command is useful to remind the user of the name of +library lemmas. + +\begin{coq_eval} +Reset Initial. +\end{coq_eval} + +\begin{coq_example} +SearchHead le. +SearchHead (@eq bool). +\end{coq_example} + +\begin{Variants} +\item +{\tt SearchHead} {\term} {\tt inside} {\module$_1$} \ldots{} {\module$_n$}{\tt .} + +This restricts the search to constructions defined in modules +{\module$_1$} \ldots{} {\module$_n$}. + +\item {\tt SearchHead} {\term} {\tt outside} {\module$_1$} \ldots{} {\module$_n$}{\tt .} + +This restricts the search to constructions not defined in modules +{\module$_1$} \ldots{} {\module$_n$}. + +\begin{ErrMsgs} +\item \errindex{Module/section \module{} not found} +No module \module{} has been required (see Section~\ref{Require}). +\end{ErrMsgs} + +\item {\tt selector: SearchHead {\term}.} + + This specifies the goal on which to search hypothesis (see + Section~\ref{tactic-syntax}). By default the 1st goal is searched. + This variant can be combined with other variants presented here. + +\end{Variants} + +\Warning Up to {\Coq} version 8.4, {\tt SearchHead} was named {\tt Search}. + +\subsection[\tt SearchPattern {\termpattern}.]{\tt SearchPattern {\term}.\comindex{SearchPattern}} + +This command displays the name and type of all hypothesis of the +current goal (if any) and theorems of the current context whose statement's +conclusion or last hypothesis and conclusion matches the expression +{\term} where holes in the latter are denoted by ``{\texttt \_}''. It +is a variant of {\tt Search + {\termpattern}} that does not look for subterms but searches for +statements whose conclusion has exactly the expected form, or whose +statement finishes by the given series of hypothesis/conclusion. + +\begin{coq_example*} +Require Import Arith. +\end{coq_example*} +\begin{coq_example} +SearchPattern (_ + _ = _ + _). +SearchPattern (nat -> bool). +SearchPattern (forall l : list _, _ l l). +\end{coq_example} + +Patterns need not be linear: you can express that the same expression +must occur in two places by using pattern variables `{\texttt +?{\ident}}''. + +\begin{coq_example} +SearchPattern (?X1 + _ = _ + ?X1). +\end{coq_example} + +\begin{Variants} +\item {\tt SearchPattern {\term} inside +{\module$_1$} \ldots{} {\module$_n$}.} + +This restricts the search to constructions defined in modules +{\module$_1$} \ldots{} {\module$_n$}. + +\item {\tt SearchPattern {\term} outside {\module$_1$} \ldots{} {\module$_n$}.} + +This restricts the search to constructions not defined in modules +{\module$_1$} \ldots{} {\module$_n$}. + +\item {\tt selector: SearchPattern {\term}.} + + This specifies the goal on which to search hypothesis (see + Section~\ref{tactic-syntax}). By default the 1st goal is searched. + This variant can be combined with other variants presented here. + +\end{Variants} + +\subsection[\tt SearchRewrite {\term}.]{\tt SearchRewrite {\term}.\comindex{SearchRewrite}} + +This command displays the name and type of all hypothesis of the +current goal (if any) and theorems of the current context whose +statement's conclusion is an equality of which one side matches the +expression {\term}. Holes in {\term} are denoted by ``{\texttt \_}''. + +\begin{coq_example} +Require Import Arith. +SearchRewrite (_ + _ + _). +\end{coq_example} + +\begin{Variants} +\item {\tt SearchRewrite {\term} inside +{\module$_1$} \ldots{} {\module$_n$}.} + +This restricts the search to constructions defined in modules +{\module$_1$} \ldots{} {\module$_n$}. + +\item {\tt SearchRewrite {\term} outside {\module$_1$} \ldots{} {\module$_n$}.} + +This restricts the search to constructions not defined in modules +{\module$_1$} \ldots{} {\module$_n$}. + +\item {\tt selector: SearchRewrite {\term}.} + + This specifies the goal on which to search hypothesis (see + Section~\ref{tactic-syntax}). By default the 1st goal is searched. + This variant can be combined with other variants presented here. + +\end{Variants} + +\subsubsection{Nota Bene:} +For the {\tt Search}, {\tt SearchHead}, {\tt SearchPattern} and +{\tt SearchRewrite} queries, it is possible to globally filter +the search results via the command +{\tt Add Search Blacklist "substring1"}. +A lemma whose fully-qualified name contains any of the declared substrings +will be removed from the search results. +The default blacklisted substrings are {\tt + "\_subproof" "Private\_"}. The command {\tt Remove Search Blacklist + ...} allows expunging this blacklist. + +% \begin{tabbing} +% \ \ \ \ \=11.\ \=\kill +% \>1.\>$A=B\mx{ if }A\stackrel{\bt{}\io{}}{\lra{}}B$\\ +% \>2.\>$\sa{}x:A.B=\sa{}y:A.B[x\la{}y]\mx{ if }y\not\in{}FV(\sa{}x:A.B)$\\ +% \>3.\>$\Pi{}x:A.B=\Pi{}y:A.B[x\la{}y]\mx{ if }y\not\in{}FV(\Pi{}x:A.B)$\\ +% \>4.\>$\sa{}x:A.B=\sa{}x:B.A\mx{ if }x\not\in{}FV(A,B)$\\ +% \>5.\>$\sa{}x:(\sa{}y:A.B).C=\sa{}x:A.\sa{}y:B[y\la{}x].C[x\la{}(x,y)]$\\ +% \>6.\>$\Pi{}x:(\sa{}y:A.B).C=\Pi{}x:A.\Pi{}y:B[y\la{}x].C[x\la{}(x,y)]$\\ +% \>7.\>$\Pi{}x:A.\sa{}y:B.C=\sa{}y:(\Pi{}x:A.B).(\Pi{}x:A.C[y\la{}(y\sm{}x)]$\\ +% \>8.\>$\sa{}x:A.unit=A$\\ +% \>9.\>$\sa{}x:unit.A=A[x\la{}tt]$\\ +% \>10.\>$\Pi{}x:A.unit=unit$\\ +% \>11.\>$\Pi{}x:unit.A=A[x\la{}tt]$ +% \end{tabbing} + +% For more informations about the exact working of this command, see +% \cite{Del97}. + +\subsection[\tt Locate {\qualid}.]{\tt Locate {\qualid}.\comindex{Locate} +\label{Locate}} +This command displays the full name of objects whose name is a prefix of the +qualified identifier {\qualid}, and consequently the \Coq\ module in which they +are defined. It searches for objects from the different qualified name spaces of +{\Coq}: terms, modules, Ltac, etc. + +\begin{coq_eval} +(*************** The last line should produce **************************) +(*********** Error: I.Dont.Exist not a defined object ******************) +\end{coq_eval} +\begin{coq_eval} +Set Printing Depth 50. +\end{coq_eval} +\begin{coq_example} +Locate nat. +Locate Datatypes.O. +Locate Init.Datatypes.O. +Locate Coq.Init.Datatypes.O. +Locate I.Dont.Exist. +\end{coq_example} + +\begin{Variants} +\item {\tt Locate Term {\qualid}.}\comindex{Locate Term}\\ + As {\tt Locate} but restricted to terms. + +\item {\tt Locate Module {\qualid}.} + As {\tt Locate} but restricted to modules. + +\item {\tt Locate Ltac {\qualid}.}\comindex{Locate Ltac}\\ + As {\tt Locate} but restricted to tactics. +\end{Variants} + + +\SeeAlso Section \ref{LocateSymbol} + +\section{Loading files} + +\Coq\ offers the possibility of loading different +parts of a whole development stored in separate files. Their contents +will be loaded as if they were entered from the keyboard. This means +that the loaded files are ASCII files containing sequences of commands +for \Coq's toplevel. This kind of file is called a {\em script} for +\Coq\index{Script file}. The standard (and default) extension of +\Coq's script files is {\tt .v}. + +\subsection[\tt Load {\ident}.]{\tt Load {\ident}.\comindex{Load}\label{Load}} +This command loads the file named {\ident}{\tt .v}, searching +successively in each of the directories specified in the {\em + loadpath}. (see Section~\ref{loadpath}) + +Files loaded this way cannot leave proofs open, and neither the {\tt + Load} command can be use inside a proof. + +\begin{Variants} +\item {\tt Load {\str}.}\label{Load-str}\\ + Loads the file denoted by the string {\str}, where {\str} is any + complete filename. Then the \verb.~. and {\tt ..} + abbreviations are allowed as well as shell variables. If no + extension is specified, \Coq\ will use the default extension {\tt + .v} +\item {\tt Load Verbose {\ident}.}, + {\tt Load Verbose {\str}}\\ + \comindex{Load Verbose} + Display, while loading, the answers of \Coq\ to each command + (including tactics) contained in the loaded file + \SeeAlso Section~\ref{Begin-Silent} +\end{Variants} + +\begin{ErrMsgs} +\item \errindex{Can't find file {\ident} on loadpath} +\item \errindex{Load is not supported inside proofs} +\item \errindex{Files processed by Load cannot leave open proofs} +\end{ErrMsgs} + +\section[Compiled files]{Compiled files\label{compiled}\index{Compiled files}} + +This section describes the commands used to load compiled files (see +Chapter~\ref{Addoc-coqc} for documentation on how to compile a file). +A compiled file is a particular case of module called {\em library file}. + +%%%%%%%%%%%% +% Import and Export described in RefMan-mod.tex +% the minor difference (to avoid multiple Exporting of libraries) in +% the treatment of normal modules and libraries by Export omitted + +\subsection[\tt Require {\qualid}.]{\tt Require {\qualid}.\label{Require} +\comindex{Require}} + +This command looks in the loadpath for a file containing +module {\qualid} and adds the corresponding module to the environment +of {\Coq}. As library files have dependencies in other library files, +the command {\tt Require {\qualid}} recursively requires all library +files the module {\qualid} depends on and adds the corresponding modules to the +environment of {\Coq} too. {\Coq} assumes that the compiled files have +been produced by a valid {\Coq} compiler and their contents are then not +replayed nor rechecked. + +To locate the file in the file system, {\qualid} is decomposed under +the form {\dirpath}{\tt .}{\textsl{ident}} and the file {\ident}{\tt +.vo} is searched in the physical directory of the file system that is +mapped in {\Coq} loadpath to the logical path {\dirpath} (see +Section~\ref{loadpath}). The mapping between physical directories and +logical names at the time of requiring the file must be consistent +with the mapping used to compile the file. If several files match, one of them +is picked in an unspecified fashion. + +\begin{Variants} +\item {\tt Require Import {\qualid}.} \comindex{Require Import} + + This loads and declares the module {\qualid} and its dependencies + then imports the contents of {\qualid} as described in + Section~\ref{Import}. + + It does not import the modules on which {\qualid} depends unless + these modules were itself required in module {\qualid} using {\tt + Require Export}, as described below, or recursively required through + a sequence of {\tt Require Export}. + + If the module required has already been loaded, {\tt Require Import + {\qualid}} simply imports it, as {\tt Import {\qualid}} would. + +\item {\tt Require Export {\qualid}.} + \comindex{Require Export} + + This command acts as {\tt Require Import} {\qualid}, but if a + further module, say {\it A}, contains a command {\tt Require + Export} {\it B}, then the command {\tt Require Import} {\it A} + also imports the module {\it B}. + +\item {\tt Require \zeroone{Import {\sl |} Export}} {\qualid}$_1$ {\ldots} {\qualid}$_n${\tt .} + + This loads the modules {\qualid}$_1$, \ldots, {\qualid}$_n$ and + their recursive dependencies. If {\tt Import} or {\tt Export} is + given, it also imports {\qualid}$_1$, \ldots, {\qualid}$_n$ and all + the recursive dependencies that were marked or transitively marked + as {\tt Export}. + +\item {\tt From {\dirpath} Require {\qualid}.} + \comindex{From Require} + + This command acts as {\tt Require}, but picks any library whose absolute name + is of the form {\tt{\dirpath}.{\dirpath'}.{\qualid}} for some {\dirpath'}. + This is useful to ensure that the {\qualid} library comes from a given + package by making explicit its absolute root. + +\end{Variants} + +\begin{ErrMsgs} + +\item \errindex{Cannot load {\qualid}: no physical path bound to {\dirpath}} + +\item \errindex{Cannot find library foo in loadpath} + + The command did not find the file {\tt foo.vo}. Either {\tt + foo.v} exists but is not compiled or {\tt foo.vo} is in a directory + which is not in your {\tt LoadPath} (see Section~\ref{loadpath}). + +\item \errindex{Compiled library {\ident}.vo makes inconsistent assumptions over library {\qualid}} + + The command tried to load library file {\ident}.vo that depends on + some specific version of library {\qualid} which is not the one + already loaded in the current {\Coq} session. Probably {\ident}.v + was not properly recompiled with the last version of the file + containing module {\qualid}. + +\item \errindex{Bad magic number} + + \index{Bad-magic-number@{\tt Bad Magic Number}} + The file {\tt{\ident}.vo} was found but either it is not a \Coq\ + compiled module, or it was compiled with an older and incompatible + version of {\Coq}. + +\item \errindex{The file {\ident}.vo contains library {\dirpath} and not + library {\dirpath'}} + + The library file {\dirpath'} is indirectly required by the {\tt + Require} command but it is bound in the current loadpath to the file + {\ident}.vo which was bound to a different library name {\dirpath} + at the time it was compiled. + +\item \errindex{Require is not allowed inside a module or a module type} + + This command is not allowed inside a module or a module type being defined. + It is meant to describe a dependency between compilation units. Note however + that the commands {\tt Import} and {\tt Export} alone can be used inside + modules (see Section~\ref{Import}). + +\end{ErrMsgs} + +\SeeAlso Chapter~\ref{Addoc-coqc} + +\subsection[\tt Print Libraries.]{\tt Print Libraries.\comindex{Print Libraries}} + +This command displays the list of library files loaded in the current +{\Coq} session. For each of these libraries, it also tells if it is +imported. + +\subsection[\tt Declare ML Module {\str$_1$} .. {\str$_n$}.]{\tt Declare ML Module {\str$_1$} .. {\str$_n$}.\comindex{Declare ML Module}} +This commands loads the {\ocaml} compiled files {\str$_1$} {\ldots} +{\str$_n$} (dynamic link). It is mainly used to load tactics +dynamically. +% (see Chapter~\ref{WritingTactics}). + The files are +searched into the current {\ocaml} loadpath (see the command {\tt +Add ML Path} in the Section~\ref{loadpath}). Loading of {\ocaml} +files is only possible under the bytecode version of {\tt coqtop} +(i.e. {\tt coqtop.byte}, see chapter +\ref{Addoc-coqc}), or when {\Coq} has been compiled with a version of +{\ocaml} that supports native {\tt Dynlink} ($\ge$ 3.11). + +\begin{Variants} +\item {\tt Local Declare ML Module {\str$_1$} .. {\str$_n$}.}\\ + This variant is not exported to the modules that import the module + where they occur, even if outside a section. +\end{Variants} + +\begin{ErrMsgs} +\item \errindex{File not found on loadpath : \str} +\item \errindex{Loading of ML object file forbidden in a native {\Coq}} +\end{ErrMsgs} + +\subsection[\tt Print ML Modules.]{\tt Print ML Modules.\comindex{Print ML Modules}} +This print the name of all \ocaml{} modules loaded with \texttt{Declare + ML Module}. To know from where these module were loaded, the user +should use the command \texttt{Locate File} (see Section~\ref{Locate File}) + +\section[Loadpath]{Loadpath} + +Loadpaths are preferably managed using {\Coq} command line options +(see Section~\ref{loadpath}) but there remain vernacular commands to +manage them for practical purposes. Such commands are only meant to be issued in +the toplevel, and using them in source files is discouraged. + +\subsection[\tt Pwd.]{\tt Pwd.\comindex{Pwd}\label{Pwd}} +This command displays the current working directory. + +\subsection[\tt Cd {\str}.]{\tt Cd {\str}.\comindex{Cd}} +This command changes the current directory according to {\str} +which can be any valid path. + +\begin{Variants} +\item {\tt Cd.}\\ + Is equivalent to {\tt Pwd.} +\end{Variants} + +\subsection[\tt Add LoadPath {\str} as {\dirpath}.]{\tt Add LoadPath {\str} as {\dirpath}.\comindex{Add LoadPath}\label{AddLoadPath}} + +This command is equivalent to the command line option {\tt -Q {\str} + {\dirpath}}. It adds the physical directory {\str} to the current {\Coq} +loadpath and maps it to the logical directory {\dirpath}. + +\begin{Variants} +\item {\tt Add LoadPath {\str}.}\\ +Performs as {\tt Add LoadPath {\str} as {\dirpath}} but for the empty directory path. +\end{Variants} + +\subsection[\tt Add Rec LoadPath {\str} as {\dirpath}.]{\tt Add Rec LoadPath {\str} as {\dirpath}.\comindex{Add Rec LoadPath}\label{AddRecLoadPath}} +This command is equivalent to the command line option {\tt -R {\str} + {\dirpath}}. It adds the physical directory {\str} and all its +subdirectories to the current {\Coq} loadpath. + +\begin{Variants} +\item {\tt Add Rec LoadPath {\str}.}\\ +Works as {\tt Add Rec LoadPath {\str} as {\dirpath}} but for the empty logical directory path. +\end{Variants} + +\subsection[\tt Remove LoadPath {\str}.]{\tt Remove LoadPath {\str}.\comindex{Remove LoadPath}} +This command removes the path {\str} from the current \Coq\ loadpath. + +\subsection[\tt Print LoadPath.]{\tt Print LoadPath.\comindex{Print LoadPath}} +This command displays the current \Coq\ loadpath. + +\begin{Variants} +\item {\tt Print LoadPath {\dirpath}.}\\ +Works as {\tt Print LoadPath} but displays only the paths that extend the {\dirpath} prefix. +\end{Variants} + +\subsection[\tt Add ML Path {\str}.]{\tt Add ML Path {\str}.\comindex{Add ML Path}} +This command adds the path {\str} to the current {\ocaml} loadpath (see +the command {\tt Declare ML Module} in the Section~\ref{compiled}). + +\subsection[\tt Add Rec ML Path {\str}.]{\tt Add Rec ML Path {\str}.\comindex{Add Rec ML Path}} +This command adds the directory {\str} and all its subdirectories +to the current {\ocaml} loadpath (see +the command {\tt Declare ML Module} in the Section~\ref{compiled}). + +\subsection[\tt Print ML Path {\str}.]{\tt Print ML Path {\str}.\comindex{Print ML Path}} +This command displays the current {\ocaml} loadpath. +This command makes sense only under the bytecode version of {\tt +coqtop}, i.e. {\tt coqtop.byte} (see the +command {\tt Declare ML Module} in the section +\ref{compiled}). + +\subsection[\tt Locate File {\str}.]{\tt Locate File {\str}.\comindex{Locate + File}\label{Locate File}} +This command displays the location of file {\str} in the current loadpath. +Typically, {\str} is a \texttt{.cmo} or \texttt{.vo} or \texttt{.v} file. + +\subsection[\tt Locate Library {\dirpath}.]{\tt Locate Library {\dirpath}.\comindex{Locate Library}\label{Locate Library}} +This command gives the status of the \Coq\ module {\dirpath}. It tells if the +module is loaded and if not searches in the load path for a module +of logical name {\dirpath}. + +\section{Backtracking} + +The backtracking commands described in this section can only be used +interactively, they cannot be part of a vernacular file loaded via +{\tt Load} or compiled by {\tt coqc}. + +\subsection[\tt Reset \ident.]{\tt Reset \ident.\comindex{Reset}} +This command removes all the objects in the environment since \ident\ +was introduced, including \ident. \ident\ may be the name of a defined +or declared object as well as the name of a section. One cannot reset +over the name of a module or of an object inside a module. + +\begin{ErrMsgs} +\item \ident: \errindex{no such entry} +\end{ErrMsgs} + +\begin{Variants} + \item {\tt Reset Initial.}\comindex{Reset Initial}\\ + Goes back to the initial state, just after the start of the + interactive session. +\end{Variants} + +\subsection[\tt Back.]{\tt Back.\comindex{Back}} + +This commands undoes all the effects of the last vernacular +command. Commands read from a vernacular file via a {\tt Load} are +considered as a single command. Proof management commands +are also handled by this command (see Chapter~\ref{Proof-handling}). +For that, {\tt Back} may have to undo more than one command in order +to reach a state where the proof management information is available. +For instance, when the last command is a {\tt Qed}, the management +information about the closed proof has been discarded. In this case, +{\tt Back} will then undo all the proof steps up to the statement of +this proof. + +\begin{Variants} +\item {\tt Back $n$} \\ + Undoes $n$ vernacular commands. As for {\tt Back}, some extra + commands may be undone in order to reach an adequate state. + For instance {\tt Back n} will not re-enter a closed proof, + but rather go just before that proof. +\end{Variants} + +\begin{ErrMsgs} +\item \errindex{Invalid backtrack} \\ + The user wants to undo more commands than available in the history. +\end{ErrMsgs} + +\subsection[\tt BackTo $\num$.]{\tt BackTo $\num$.\comindex{BackTo}} +\label{sec:statenums} + +This command brings back the system to the state labeled $\num$, +forgetting the effect of all commands executed after this state. +The state label is an integer which grows after each successful command. +It is displayed in the prompt when in \texttt{-emacs} mode. +Just as {\tt Back} (see above), the {\tt BackTo} command now handles +proof states. For that, it may have to undo some +extra commands and end on a state $\num' \leq \num$ if necessary. + +\begin{Variants} +\item {\tt Backtrack $\num_1$ $\num_2$ $\num_3$}.\comindex{Backtrack}\\ + {\tt Backtrack} is a \emph{deprecated} form of {\tt BackTo} which + allows explicitly manipulating the proof environment. The three + numbers $\num_1$, $\num_2$ and $\num_3$ represent the following: +\begin{itemize} +\item $\num_3$: Number of \texttt{Abort} to perform, i.e. the number + of currently opened nested proofs that must be canceled (see + Chapter~\ref{Proof-handling}). +\item $\num_2$: \emph{Proof state number} to unbury once aborts have + been done. {\Coq} will compute the number of \texttt{Undo} to perform + (see Chapter~\ref{Proof-handling}). +\item $\num_1$: State label to reach, as for {\tt BackTo}. +\end{itemize} +\end{Variants} + +\begin{ErrMsgs} +\item \errindex{Invalid backtrack} \\ + The destination state label is unknown. +\end{ErrMsgs} + +\section{Quitting and debugging} + +\subsection[\tt Quit.]{\tt Quit.\comindex{Quit}} +This command permits to quit \Coq. + +\subsection[\tt Drop.]{\tt Drop.\comindex{Drop}\label{Drop}} + +This is used mostly as a debug facility by \Coq's implementors +and does not concern the casual user. +This command permits to leave {\Coq} temporarily and enter the +{\ocaml} toplevel. The {\ocaml} command: + +\begin{flushleft} +\begin{verbatim} +#use "include";; +\end{verbatim} +\end{flushleft} + +\noindent add the right loadpaths and loads some toplevel printers for +all abstract types of \Coq - section\_path, identifiers, terms, judgments, +\dots. You can also use the file \texttt{base\_include} instead, +that loads only the pretty-printers for section\_paths and +identifiers. +% See Section~\ref{test-and-debug} more information on the +% usage of the toplevel. +You can return back to \Coq{} with the command: + +\begin{flushleft} +\begin{verbatim} +go();; +\end{verbatim} +\end{flushleft} + +\begin{Warnings} +\item It only works with the bytecode version of {\Coq} (i.e. {\tt coqtop} called with option {\tt -byte}, see the contents of Section~\ref{binary-images}). +\item You must have compiled {\Coq} from the source package and set the + environment variable \texttt{COQTOP} to the root of your copy of the sources (see Section~\ref{EnvVariables}). +\end{Warnings} + +\subsection[\tt Time \textrm{\textsl{command}}.]{\tt Time \textrm{\textsl{command}}.\comindex{Time} +\label{time}} +This command executes the vernacular command \textrm{\textsl{command}} +and display the time needed to execute it. + +\subsection[\tt Redirect "\textrm{\textsl{file}}" \textrm{\textsl{command}}.]{\tt Redirect "\textrm{\textsl{file}}" \textrm{\textsl{command}}.\comindex{Redirect} +\label{redirect}} +This command executes the vernacular command \textrm{\textsl{command}}, redirecting its output to ``\textrm{\textsl{file}}.out''. + +\subsection[\tt Timeout \textrm{\textsl{int}} \textrm{\textsl{command}}.]{\tt Timeout \textrm{\textsl{int}} \textrm{\textsl{command}}.\comindex{Timeout} +\label{timeout}} + +This command executes the vernacular command \textrm{\textsl{command}}. If +the command has not terminated after the time specified by the integer +(time expressed in seconds), then it is interrupted and an error message +is displayed. + +\subsection[\tt Set Default Timeout \textrm{\textsl{int}}.]{\tt Set + Default Timeout \textrm{\textsl{int}}.\optindex{Default Timeout}} + +After using this command, all subsequent commands behave as if they +were passed to a {\tt Timeout} command. Commands already starting by +a {\tt Timeout} are unaffected. + +\subsection[\tt Unset Default Timeout.]{\tt Unset Default Timeout.\optindex{Default Timeout}} + +This command turns off the use of a default timeout. + +\subsection[\tt Test Default Timeout.]{\tt Test Default Timeout.\optindex{Default Timeout}} + +This command displays whether some default timeout has be set or not. + +\subsection[\tt Fail \textrm{\textsl{command-or-tactic}}.]{\tt Fail \textrm{\textsl{command-or-tactic}}.\comindex{Fail}\label{Fail}} + +For debugging {\Coq} scripts, sometimes it is desirable to know +whether a command or a tactic fails. If the given command or tactic +fails, the {\tt Fail} statement succeeds, without changing the proof +state, and in interactive mode, {\Coq} prints a message confirming the failure. +If the command or tactic succeeds, the statement is an error, and +{\Coq} prints a message indicating that the failure did not occur. + +\section{Controlling display} + +\subsection[\tt Set Silent.]{\tt Set Silent.\optindex{Silent} +\label{Begin-Silent} +\index{Silent mode}} +This command turns off the normal displaying. + +\subsection[\tt Unset Silent.]{\tt Unset Silent.\optindex{Silent}} +This command turns the normal display on. + +\subsection[\tt Set Warnings ``(\nterm{w}$_1$,\ldots,% + \nterm{w}$_n$)''.]{{\tt Set Warnings ``(\nterm{w}$_1$,\ldots,% + \nterm{w}$_n$)''}.\optindex{Warnings}} +\label{SetWarnings} +This command configures the display of warnings. It is experimental, and +expects, between quotes, a comma-separated list of warning names or +categories. Adding~\texttt{-} in front of a warning or category disables it, +adding~\texttt{+} makes it an error. It is possible to use the special +categories \texttt{all} and \texttt{default}, the latter containing the warnings +enabled by default. The flags are interpreted from left to right, so in case of +an overlap, the flags on the right have higher priority, meaning that +\texttt{A,-A} is equivalent to \texttt{-A}. + +\subsection[\tt Set Search Output Name Only.]{\tt Set Search Output Name Only.\optindex{Search Output Name Only} +\label{Search-Output-Name-Only} +\index{Search Output Name Only mode}} +This command restricts the output of search commands to identifier names; turning it on causes invocations of {\tt Search}, {\tt SearchHead}, {\tt SearchPattern}, {\tt SearchRewrite} etc. to omit types from their output, printing only identifiers. + +\subsection[\tt Unset Search Output Name Only.]{\tt Unset Search Output Name Only.\optindex{Search Output Name Only}} +This command turns type display in search results back on. + +\subsection[\tt Set Printing Width {\integer}.]{\tt Set Printing Width {\integer}.\optindex{Printing Width}} +\label{SetPrintingWidth} +This command sets which left-aligned part of the width of the screen +is used for display. + +\subsection[\tt Unset Printing Width.]{\tt Unset Printing Width.\optindex{Printing Width}} +This command resets the width of the screen used for display to its +default value (which is 78 at the time of writing this documentation). + +\subsection[\tt Test Printing Width.]{\tt Test Printing Width.\optindex{Printing Width}} +This command displays the current screen width used for display. + +\subsection[\tt Set Printing Depth {\integer}.]{\tt Set Printing Depth {\integer}.\optindex{Printing Depth}} +This command sets the nesting depth of the formatter used for +pretty-printing. Beyond this depth, display of subterms is replaced by +dots. + +\subsection[\tt Unset Printing Depth.]{\tt Unset Printing Depth.\optindex{Printing Depth}} +This command resets the nesting depth of the formatter used for +pretty-printing to its default value (at the +time of writing this documentation, the default value is 50). + +\subsection[\tt Test Printing Depth.]{\tt Test Printing Depth.\optindex{Printing Depth}} +This command displays the current nesting depth used for display. + +\subsection[\tt Unset Printing Compact Contexts.]{\tt Unset Printing Compact Contexts.\optindex{Printing Compact Contexts}} +This command resets the displaying of goals contexts to non compact +mode (default at the time of writing this documentation). Non compact +means that consecutive variables of different types are printed on +different lines. + +\subsection[\tt Set Printing Compact Contexts.]{\tt Set Printing Compact Contexts.\optindex{Printing Compact Contexts}} +This command sets the displaying of goals contexts to compact mode. +The printer tries to reduce the vertical size of goals contexts by +putting several variables (even if of different types) on the same +line provided it does not exceed the printing width (See {\tt Set + Printing Width} above). + +\subsection[\tt Test Printing Compact Contexts.]{\tt Test Printing Compact Contexts.\optindex{Printing Compact Contexts}} +This command displays the current state of compaction of goal. + + +\subsection[\tt Unset Printing Unfocused.]{\tt Unset Printing Unfocused.\optindex{Printing Unfocused}} +This command resets the displaying of goals to focused goals only +(default). Unfocused goals are created by focusing other goals with +bullets(see~\ref{bullets}) or curly braces (see~\ref{curlybacket}). + +\subsection[\tt Set Printing Unfocused.]{\tt Set Printing Unfocused.\optindex{Printing Unfocused}} +This command enables the displaying of unfocused goals. The goals are +displayed after the focused ones and are distinguished by a separator. + +\subsection[\tt Test Printing Unfocused.]{\tt Test Printing Unfocused.\optindex{Printing Unfocused}} +This command displays the current state of unfocused goals display. + +\subsection[\tt Set Printing Dependent Evars Line.]{\tt Set Printing Dependent Evars Line.\optindex{Printing Dependent Evars Line}} +This command enables the printing of the ``{\tt (dependent evars: \ldots)}'' +line when {\tt -emacs} is passed. + +\subsection[\tt Unset Printing Dependent Evars Line.]{\tt Unset Printing Dependent Evars Line.\optindex{Printing Dependent Evars Line}} +This command disables the printing of the ``{\tt (dependent evars: \ldots)}'' +line when {\tt -emacs} is passed. + +%\subsection{\tt Abstraction ...} +%Not yet documented. + +\section{Controlling the reduction strategies and the conversion algorithm} +\label{Controlling_reduction_strategy} + +{\Coq} provides reduction strategies that the tactics can invoke and +two different algorithms to check the convertibility of types. +The first conversion algorithm lazily +compares applicative terms while the other is a brute-force but efficient +algorithm that first normalizes the terms before comparing them. The +second algorithm is based on a bytecode representation of terms +similar to the bytecode representation used in the ZINC virtual +machine~\cite{Leroy90}. It is especially useful for intensive +computation of algebraic values, such as numbers, and for reflection-based +tactics. The commands to fine-tune the reduction strategies and the +lazy conversion algorithm are described first. + +\subsection[{\tt Opaque} \qualid$_1$ {\ldots} \qualid$_n${\tt .}]{{\tt Opaque} \qualid$_1$ {\ldots} \qualid$_n${\tt .}\comindex{Opaque}\label{Opaque}} +This command has an effect on unfoldable constants, i.e. +on constants defined by {\tt Definition} or {\tt Let} (with an explicit +body), or by a command assimilated to a definition such as {\tt +Fixpoint}, {\tt Program Definition}, etc, or by a proof ended by {\tt +Defined}. The command tells not to unfold +the constants {\qualid$_1$} {\ldots} {\qualid$_n$} in tactics using +$\delta$-conversion (unfolding a constant is replacing it by its +definition). + +{\tt Opaque} has also an effect on the conversion algorithm of {\Coq}, +telling it to delay the unfolding of a constant as much as possible when +{\Coq} has to check the conversion (see Section~\ref{conv-rules}) +of two distinct applied constants. + +The scope of {\tt Opaque} is limited to the current section, or +current file, unless the variant {\tt Global Opaque \qualid$_1$ {\ldots} +\qualid$_n$} is used. + +\SeeAlso sections \ref{Conversion-tactics}, \ref{Automatizing}, +\ref{Theorem} + +\begin{ErrMsgs} +\item \errindex{The reference \qualid\ was not found in the current +environment}\\ + There is no constant referred by {\qualid} in the environment. + Nevertheless, if you asked \texttt{Opaque foo bar} + and if \texttt{bar} does not exist, \texttt{foo} is set opaque. +\end{ErrMsgs} + +\subsection[{\tt Transparent} \qualid$_1$ {\ldots} \qualid$_n${\tt .}]{{\tt Transparent} \qualid$_1$ {\ldots} \qualid$_n${\tt .}\comindex{Transparent}\label{Transparent}} +This command is the converse of {\tt Opaque} and it applies on +unfoldable constants to restore their unfoldability after an {\tt +Opaque} command. + +Note in particular that constants defined by a proof ended by {\tt +Qed} are not unfoldable and {\tt Transparent} has no effect on +them. This is to keep with the usual mathematical practice of {\em +proof irrelevance}: what matters in a mathematical development is the +sequence of lemma statements, not their actual proofs. This +distinguishes lemmas from the usual defined constants, whose actual +values are of course relevant in general. + +The scope of {\tt Transparent} is limited to the current section, or +current file, unless the variant {\tt Global Transparent} \qualid$_1$ +{\ldots} \qualid$_n$ is used. + +\begin{ErrMsgs} +% \item \errindex{Can not set transparent.}\\ +% It is a constant from a required module or a parameter. +\item \errindex{The reference \qualid\ was not found in the current +environment}\\ + There is no constant referred by {\qualid} in the environment. +\end{ErrMsgs} + +\SeeAlso sections \ref{Conversion-tactics}, \ref{Automatizing}, +\ref{Theorem} + +\subsection{{\tt Strategy} {\it level} {\tt [} \qualid$_1$ {\ldots} \qualid$_n$ + {\tt ].}\comindex{Strategy}\comindex{Local Strategy}\label{Strategy}} +This command generalizes the behavior of {\tt Opaque} and {\tt + Transparent} commands. It is used to fine-tune the strategy for +unfolding constants, both at the tactic level and at the kernel +level. This command associates a level to \qualid$_1$ {\ldots} +\qualid$_n$. Whenever two expressions with two distinct head +constants are compared (for instance, this comparison can be triggered +by a type cast), the one with lower level is expanded first. In case +of a tie, the second one (appearing in the cast type) is expanded. + +Levels can be one of the following (higher to lower): +\begin{description} +\item[opaque]: level of opaque constants. They cannot be expanded by + tactics (behaves like $+\infty$, see next item). +\item[\num]: levels indexed by an integer. Level $0$ corresponds + to the default behavior, which corresponds to transparent + constants. This level can also be referred to as {\bf transparent}. + Negative levels correspond to constants to be expanded before normal + transparent constants, while positive levels correspond to constants + to be expanded after normal transparent constants. +\item[expand]: level of constants that should be expanded first + (behaves like $-\infty$) +\end{description} + +These directives survive section and module closure, unless the +command is prefixed by {\tt Local}. In the latter case, the behavior +regarding sections and modules is the same as for the {\tt + Transparent} and {\tt Opaque} commands. + +\subsection{{\tt Print Strategy} \qualid{\tt .}\comindex{Print Strategy}\label{PrintStrategy}} + +This command prints the strategy currently associated to \qualid{}. It fails if +\qualid{} is not an unfoldable reference, that is, neither a variable nor a +constant. + +\begin{ErrMsgs} +\item The reference is not unfoldable. +\end{ErrMsgs} + +\begin{Variants} +\item {\tt Print Strategies}\comindex{Print Strategies}\\ + Print all the currently non-transparent strategies. +\end{Variants} + +\subsection{\tt Declare Reduction \ident\ := {\rm\sl convtactic}.} + +This command allows giving a short name to a reduction expression, +for instance {\tt lazy beta delta [foo bar]}. This short name can +then be used in {\tt Eval \ident\ in ...} or {\tt eval} directives. +This command accepts the {\tt Local} modifier, for discarding +this reduction name at the end of the file or module. For the moment +the name cannot be qualified. In particular declaring the same name +in several modules or in several functor applications will be refused +if these declarations are not local. The name \ident\ cannot be used +directly as an Ltac tactic, but nothing prevent the user to also +perform a {\tt Ltac \ident\ := {\rm\sl convtactic}}. + +\SeeAlso sections \ref{Conversion-tactics} + +\section{Controlling the locality of commands} + +\subsection{{\tt Local}, {\tt Global} +\comindex{Local} +\comindex{Global} +} + +Some commands support a {\tt Local} or {\tt Global} prefix modifier to +control the scope of their effect. There are four kinds of commands: + +\begin{itemize} +\item Commands whose default is to extend their effect both outside the + section and the module or library file they occur in. + + For these commands, the {\tt Local} modifier limits the effect of + the command to the current section or module it occurs in. + + As an example, the {\tt Coercion} (see Section~\ref{Coercions}) + and {\tt Strategy} (see Section~\ref{Strategy}) + commands belong to this category. + +\item Commands whose default behavior is to stop their effect at the + end of the section they occur in but to extent their effect outside + the module or library file they occur in. + + For these commands, the {\tt Local} modifier limits the effect of + the command to the current module if the command does not occur in a + section and the {\tt Global} modifier extends the effect outside the + current sections and current module if the command occurs in a + section. + + As an example, the {\tt Implicit Arguments} (see + Section~\ref{Implicit Arguments}), {\tt Ltac} (see + Chapter~\ref{TacticLanguage}) or {\tt Notation} (see + Section~\ref{Notation}) commands belong to this category. + + Notice that a subclass of these commands do not support extension of + their scope outside sections at all and the {\tt Global} is not + applicable to them. + +\item Commands whose default behavior is to stop their effect at the + end of the section or module they occur in. + + For these commands, the {\tt Global} modifier extends their effect + outside the sections and modules they occurs in. + + The {\tt Transparent} and {\tt Opaque} (see + Section~\ref{Controlling_reduction_strategy}) commands belong to + this category. + +\item Commands whose default behavior is to extend their effect + outside sections but not outside modules when they occur in a + section and to extend their effect outside the module or library + file they occur in when no section contains them. + + For these commands, the {\tt Local} modifier limits the effect to + the current section or module while the {\tt Global} modifier extends + the effect outside the module even when the command occurs in a section. + + The {\tt Set} and {\tt Unset} commands belong to this category. +\end{itemize} + + +%%% Local Variables: +%%% mode: latex +%%% TeX-master: "Reference-Manual" +%%% End: |