Coq tactic:

- documentation
- better error message when prover name is invalid
- no shortcut tactic ae, Z3, etc. anymore

doc/coq_tactic.tex

@@ -2,4 +2,64 @@
 \label{chap:tactic}
 \index{Coq proof assistant}
 
-\todo{}
+\why\ provides a Coq tactic to call external theorem provers as oracles.
+
+\section{Installation}
+
+You need Coq version 8.3 or greater. If this is the case, \why's
+configuration detects it, then compiles and installs the Coq tactic.
+The Coq tactic is installed in
+\begin{center}
+  \textit{why3-lib-dir}\texttt{/coq-tactic/}
+\end{center}
+where \textit{why3-lib-dir} is \why's library directory, that is typically
+\texttt{/usr/lib/why3} or \texttt{/usr/local/lib/why3}. This directory
+is automatically added to Coq's load path if you are
+calling Coq via \why (from \texttt{why3ide}, \texttt{why3replayer},
+etc.). If you are calling Coq by yourself, you need to add
+this directory to Coq's load path, either using Coq's command line
+option \texttt{-I} or by adding
+\begin{center}
+  \verb+Add LoadPath "+\textit{why3-lib-dir}\verb+/coq-tactic/".+
+\end{center}
+to your \texttt{\~{}/.coqrc} resource file.
+
+\section{Usage}
+
+The Coq tactic is called \texttt{why3} and is used as follows:
+\begin{center}
+  \texttt{why3} \verb+"+\textit{prover-name}\verb+"+
+  $[$\texttt{timelimit} \textit{n}$]$.
+\end{center}
+The string \textit{prover-name} identifies one of the automated theorem provers
+supported by \why, as reported by \verb+why3 --list-provers+.
+The current goal is then translated to \why's logic and the prover is
+called. If it reports the goal to be valid, then Coq's \texttt{admit}
+tactic is used to assume the goal. The prover is called with a time
+limit in seconds as given by \why's configuration file
+(see page~\pageref{sec:whyconffile}). A different value may be given
+using the \texttt{timelimit} keyword.
+
+\paragraph{Error messages.} The following errors may be reported by
+the Coq tactic.
+\begin{description}
+\item[\texttt{Not a first order goal}] ~\par
+  The Coq goal could not be translated to \why's logic.
+\item[\texttt{Timeout}] ~\par
+  There was no answer from the prover within the given time limit.
+\item[\texttt{Don't know}] ~\par
+  The prover stopped without validating the goal.
+\item[\texttt{Invalid}] ~\par
+  The prover stopped, reporting the goal to be invalid.
+\item[\texttt{Failure}] ~\par
+  The prover failed. Depending on the message that follows, you may
+  want to file a bug report, either to the \why\ developers or to the
+  prover developers.
+\end{description}
+
+%%% Local Variables:
+%%% mode: latex
+%%% compile-command: "make -C .. doc"
+%%% TeX-PDF-mode: t
+%%% TeX-master: "manual"
+%%% End:

doc/manpages.tex

@@ -846,6 +846,7 @@ to verified goals.
 
 \section{The \texttt{why3.conf} configuration file}
 \label{sec:whyconffile}
+\index{why3.conf@\texttt{why3.conf}}\index{configuration file}
 
 \todo{THIS SECTION IS OUTDATED}
 

examples/programs/power/power_Power_Power_sum_1.v

@@ -13,6 +13,8 @@ Axiom Power_s : forall (x:Z) (n:Z), (0%Z <  n)%Z -> ((power x
 
 Axiom Power_1 : forall (x:Z), ((power x 1%Z) = x).
 
+Require Import Why3.
+
 (* Why3 goal *)
 Theorem Power_sum : forall (x:Z) (n:Z) (m:Z), (0%Z <= n)%Z ->
   ((0%Z <= m)%Z -> ((power x (n + m)%Z) = ((power x n) * (power x m))%Z)).
@@ -21,11 +23,8 @@ intros x n m Hn Hm.
 generalize Hm.
 pattern m.
 apply Z_lt_induction; auto.
+why3 "alt-ergo".
 (*
-ae.
-
-ca marche !!
-*)
 intros n0 Hind Hn0.
 assert (h:(n0 = 0 \/ n0 > 0)%Z) by omega.
 destruct h.
@@ -36,6 +35,7 @@ rewrite Hind; auto with zarith.
 rewrite (Power_s x n0).
 ring.
 omega.
+*)
 Qed.
 
 

examples/programs/vacid_0_sparse_array/vacid_0_sparse_array_WP_SparseArray_permutation_1.v

@@ -160,13 +160,8 @@ Definition range(a:(map Z Z)) (n:Z): Prop := forall (i:Z), ((0%Z <= i)%Z /\
 Axiom injective_surjective : forall (a:(map Z Z)) (n:Z), (injective a n) ->
   ((range a n) -> (surjective a n)).
 
-(*
-Add LoadPath "~/why3/src/coq-plugin".
-Declare ML Module "whytac".
-Ltac ae := why3 "alt-ergo".
-*)
-
 Require Import Why3.
+Ltac ae := why3 "alt-ergo".
 
 (* Why3 goal *)
 Theorem permutation : forall (a:Type), forall (a1:(sparse_array a)),

examples/programs/vacid_0_sparse_array/why3session.xml

@@ -137,11 +137,11 @@
     shape="ais_eltV0V1Iainfix <V1alengthV0Aainfix <=c0V1FIainfix =acardV0alengthV0Iasa_invV0F">
     <proof
      prover="2"
-     timelimit="15"
+     timelimit="10"
      edited="vacid_0_sparse_array_WP_SparseArray_permutation_1.v"
      obsolete="false"
      archived="false">
-     <result status="valid" time="1.10"/>
+     <result status="valid" time="1.15"/>
     </proof>
    </goal>
    <goal

lib/coq-tactic/Why3.v

 Declare ML Module "why3tac".
-
-Ltac ae := why3 "alt-ergo".
-Ltac Z3 := why3 "z3-2".
-Ltac spass := why3 "spass".

src/coq-tactic/g_why3tac.ml4

@@ -24,4 +24,5 @@ open Why3tac
 
 TACTIC EXTEND Why3
   [ "why3" string(s) ] -> [ why3tac s ]
+| [ "why3" string(s) "timelimit" integer(n) ] -> [ why3tac ~timelimit:n s ]
 END

src/coq-tactic/test.v

@@ -3,6 +3,8 @@ Require Export ZArith.
 Open Scope Z_scope.
 Require Export List.
 
+Ltac ae := why3 "alt-ergo".
+
 Section S0.
   Variable a:Set->Set.
 

src/coq-tactic/why3tac.ml

@@ -1085,7 +1085,7 @@ let tr_top_decl = function
   | _, Lib.ClosedSection _
   | _, Lib.FrozenState _ -> ()
 
-let why3tac s gl =
+let why3tac ?(timelimit=timelimit) s gl =
   (* print_dep Format.err_formatter; *)
   let concl_type = pf_type_of gl (pf_concl gl) in
   if not (is_Prop concl_type) then error "Conclusion is not a Prop";
@@ -1113,6 +1113,13 @@ let why3tac s gl =
     | NotFO ->
         if debug then Printexc.print_backtrace stderr; flush stderr;
         error "Not a first order goal"
+    | Whyconf.ProverNotFound (_, s) ->
+        let pl = Mprover.fold (fun _ p l -> p.id :: l)
+          (get_provers config) [] in
+        let msg = pr_str "No such prover `" ++ pr_str s ++ pr_str "'." ++
+          pr_spc () ++ pr_str "Available provers are:" ++ pr_fnl () ++
+          prlist (fun s -> pr_str s ++ pr_fnl ()) (List.rev pl) in
+        errorlabstrm "Whyconf.ProverNotFound" msg
     | e ->
         Printexc.print_backtrace stderr; flush stderr;
         Format.eprintf "@[exception: %a@]@." Exn_printer.exn_printer e;
@@ -1120,6 +1127,6 @@ let why3tac s gl =
 
 (*
 Local Variables:
-compile-command: "unset LANG; make -C ../.. src/coq-plugin/why3tac.cmxs"
+compile-command: "unset LANG; make -C ../.. lib/coq-tactic/why3tac.cmxs"
 End:
 *)