ocaml 3.09 transition

[helm.git] / helm / ocaml / tactics / equalityTactics.ml

diff --git a/helm/ocaml/tactics/equalityTactics.ml b/helm/ocaml/tactics/equalityTactics.ml
index 20dede31e902f3dc94d0a5c7aded2ecfac7f893a..7ed946170b5e36e018304c7062a033f96a4cb20c 100644 (file)
--- a/helm/ocaml/tactics/equalityTactics.ml
+++ b/helm/ocaml/tactics/equalityTactics.ml
@@ -23,8 +23,8 @@
  * http://cs.unibo.it/helm/.
  *)
  
-let rewrite_tac ~direction ~pattern equality =
- let rewrite_tac ~direction ~pattern:(wanted,hyps_pat,concl_pat) equality status
+let rec rewrite_tac ~direction ~pattern equality =
+ let _rewrite_tac ~direction ~pattern:(wanted,hyps_pat,concl_pat) equality status
  =
   let module C = Cic in
   let module U = UriManager in
@@ -33,21 +33,35 @@ let rewrite_tac ~direction ~pattern equality =
   let module PEH = ProofEngineHelpers in
   let module PT = PrimitiveTactics in
   assert (wanted = None);   (* this should be checked syntactically *)
-  (*assert (hyps_pat = []); (*CSC: not implemented yet! *)*)
   let proof,goal = status in
   let curi, metasenv, pbo, pty = proof in
   let (metano,context,gty) as conjecture = CicUtil.lookup_meta goal metasenv in
+  match hyps_pat with
+     he::(_::_ as tl) ->
+       PET.apply_tactic
+        (Tacticals.then_
+          (rewrite_tac ~direction
+           ~pattern:(None,[he],Cic.Implicit None) equality)
+          (rewrite_tac ~direction ~pattern:(None,tl,concl_pat) equality)
+        ) status
+   | [_] as hyps_pat when concl_pat <> Cic.Implicit None ->
+       PET.apply_tactic
+        (Tacticals.then_
+          (rewrite_tac ~direction
+           ~pattern:(None,hyps_pat,Cic.Implicit None) equality)
+          (rewrite_tac ~direction ~pattern:(None,[],concl_pat) equality)
+        ) status
+   | _ ->
   let arg,dir2,tac,concl_pat,gty =
    match hyps_pat with
-      [] -> None,true,PT.exact_tac,concl_pat,gty
+      [] -> None,true,(fun ~term _ -> PT.exact_tac term),concl_pat,gty
     | [name,pat] ->
-      (*CSC: bug here; I am ignoring the concl_pat *)
       let rec find_hyp n =
        function
           [] -> assert false
         | Some (Cic.Name s,Cic.Decl ty)::_ when name = s ->
            Cic.Rel n, CicSubstitution.lift n ty
-        | Some (Cic.Name s,Cic.Def _)::_ -> assert false (*CSC: not implemented yet!*)
+        | Some (Cic.Name s,Cic.Def _)::_ -> assert false (*CSC: not implemented yet! But does this make any sense?*)
         | _::tl -> find_hyp (n+1) tl
       in
        let arg,gty = find_hyp 1 context in
@@ -60,20 +74,21 @@ let rewrite_tac ~direction ~pattern equality =
        in
         let dummy = "dummy" in
         Some arg,false,
-         (fun ~term ->
+         (fun ~term typ ->
            Tacticals.seq
             ~tactics:
               [ProofEngineStructuralRules.rename name dummy;
                PT.letin_tac
                 ~mk_fresh_name_callback:(fun _ _ _ ~typ -> Cic.Name name) term;
                ProofEngineStructuralRules.clearbody name;
-               ReductionTactics.simpl_tac
+               ReductionTactics.change_tac
                 ~pattern:
-                  (None,[name,Cic.Implicit (Some `Hole)],Cic.Implicit None);
+                  (None,[name,Cic.Implicit (Some `Hole)],Cic.Implicit None)
+                (ProofEngineTypes.const_lazy_term typ);
                ProofEngineStructuralRules.clear dummy
               ]),
          pat,gty
-    | _ -> assert false (*CSC: not implemented yet!*)
+    | _::_ -> assert false
   in
   let if_right_to_left do_not_change a b = 
     match direction with
@@ -139,23 +154,24 @@ let rewrite_tac ~direction ~pattern equality =
   let pred = C.Lambda (fresh_name, ty, abstr_gty) in
   (* The argument is either a meta if we are rewriting in the conclusion
      or the hypothesis if we are rewriting in an hypothesis *)
-  let metasenv',arg =
+  let metasenv',arg,newtyp =
    match arg with
       None ->
        let gty' = CicSubstitution.subst t2 abstr_gty in
        let irl =
         CicMkImplicit.identity_relocation_list_for_metavariable context in
        let metasenv' = (fresh_meta,context,gty')::metasenv' in
-        metasenv', C.Meta (fresh_meta,irl)
+        metasenv', C.Meta (fresh_meta,irl), Cic.Rel (-1) (* dummy term, never used *)
     | Some arg ->
-       metasenv,arg
+       let gty' = CicSubstitution.subst t1 abstr_gty in
+        metasenv,arg,gty'
   in
   let exact_proof = 
     C.Appl [eq_ind ; ty ; t2 ; pred ; arg ; t1 ;equality]
   in
   let (proof',goals) =
     PET.apply_tactic 
-      (tac ~term:exact_proof) ((curi,metasenv',pbo,pty),goal)
+      (tac ~term:exact_proof newtyp) ((curi,metasenv',pbo,pty),goal)
   in
   let goals =
    goals@(ProofEngineHelpers.compare_metasenvs ~oldmetasenv:metasenv
@@ -163,7 +179,7 @@ let rewrite_tac ~direction ~pattern equality =
   in
    (proof',goals)
  in
-  ProofEngineTypes.mk_tactic (rewrite_tac ~direction ~pattern equality)
+  ProofEngineTypes.mk_tactic (_rewrite_tac ~direction ~pattern equality)
   
  
 let rewrite_simpl_tac ~direction ~pattern equality =