1. new syntax for patterns:

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

diff --git a/helm/ocaml/tactics/variousTactics.ml b/helm/ocaml/tactics/variousTactics.ml
index 226a8c87c831d29531078d1d56707ec3e9a919e0..2e6810387455602779d23bb9642ae29e2de2c750 100644 (file)
--- a/helm/ocaml/tactics/variousTactics.ml
+++ b/helm/ocaml/tactics/variousTactics.ml
@@ -63,6 +63,8 @@ let assumption_tac =
 
 (* ANCORA DA DEBUGGARE *)
 
+exception UnableToDetectTheTermThatMustBeGeneralizedYouMustGiveItExplicitly;;
+exception TheSelectedTermsMustLiveInTheGoalContext
 exception AllSelectedTermsMustBeConvertible;;
 exception CannotGeneralizeInHypotheses;;
 
@@ -72,10 +74,12 @@ contesto e si lifta di tot... COSA SIGNIFICA TUTTO CIO'?????? *)
 
 let generalize_tac 
  ?(mk_fresh_name_callback = FreshNamesGenerator.mk_fresh_name ~subst:[])
- ~term pattern
+ pattern
  =
   let module PET = ProofEngineTypes in
-  let generalize_tac mk_fresh_name_callback ~term (hyps_pat,concl_pat) status =
+  let generalize_tac mk_fresh_name_callback
+       ~pattern:(term,hyps_pat,concl_pat) status
+  =
    if hyps_pat <> [] then raise CannotGeneralizeInHypotheses ;
    let (proof, goal) = status in
    let module C = Cic in
@@ -83,36 +87,48 @@ let generalize_tac
    let module T = Tacticals in
     let _,metasenv,_,_ = proof in
     let _,context,ty = CicUtil.lookup_meta goal metasenv in
-    let terms =
-     let path =
-      match concl_pat with
-         None -> Cic.Implicit (Some `Hole)
-       | Some path -> path in
-     let roots = ProofEngineHelpers.select ~term:ty ~pattern:path in
-      List.fold_left
-       (fun acc (i, r) -> 
-         ProofEngineHelpers.find_subterms
-          ~eq:ProofEngineReduction.alpha_equivalence ~wanted:term r @ acc
-       ) [] roots
-    in
-     let typ =
-      let typ,u =
-       CicTypeChecker.type_of_aux' metasenv context term CicUniv.empty_ugraph in
-      (* We need to check that all the convertibility of all the terms *)
-      ignore (
-       (* TASSI: FIXME *)
-       List.fold_left
-        (fun u t ->
-          let b,u1 = CicReduction.are_convertible context term t u in 
-           if not b then 
-            raise AllSelectedTermsMustBeConvertible
-           else
-            u1
-        ) u terms) ;
-       typ
-     in
-      PET.apply_tactic 
-      (T.thens 
+    let terms_with_context =
+     ProofEngineHelpers.select ~context ~term:ty ~pattern:(term,concl_pat) in
+    let typ,term =
+     match terms_with_context, term with
+        [], None ->
+         raise UnableToDetectTheTermThatMustBeGeneralizedYouMustGiveItExplicitly
+      | _, Some term
+      | (_,term)::_, None ->
+         fst
+          (CicTypeChecker.type_of_aux' metasenv context term
+            CicUniv.empty_ugraph),
+         term in
+    (* We need to check:
+        1. whether they live in the context of the goal;
+           if they do they are also well-typed since they are closed subterms
+           of a well-typed term in the well-typed context of the well-typed
+           term
+        2. whether they are convertible
+    *)
+    ignore (
+     (* TASSI: FIXME *)
+     List.fold_left
+      (fun u (context_of_t,t) ->
+        (* 1 *)
+        begin
+         try
+          ignore
+           (CicMetaSubst.delift_rels [] metasenv
+             (List.length context_of_t - List.length context) t)
+         with
+          CicMetaSubst.DeliftingARelWouldCaptureAFreeVariable ->
+           raise TheSelectedTermsMustLiveInTheGoalContext
+        end;
+        (* 2 *)
+        let b,u1 = CicReduction.are_convertible context term t u in 
+         if not b then 
+          raise AllSelectedTermsMustBeConvertible
+         else
+          u1
+      ) CicUniv.empty_ugraph terms_with_context) ;
+    PET.apply_tactic 
+     (T.thens 
        ~start:
          (P.cut_tac 
           (C.Prod(
@@ -120,8 +136,8 @@ let generalize_tac
             typ,
             (ProofEngineReduction.replace_lifting_csc 1
               ~equality:(==) 
-              ~what:terms
-              ~with_what:(List.map (function _ -> C.Rel 1) terms)
+              ~what:(List.map snd terms_with_context)
+              ~with_what:(List.map (function _ -> C.Rel 1) terms_with_context)
               ~where:ty)
           )))
        ~continuations:
@@ -129,5 +145,5 @@ let generalize_tac
            T.id_tac])
        status
  in
-  PET.mk_tactic (generalize_tac mk_fresh_name_callback ~term pattern)
+  PET.mk_tactic (generalize_tac mk_fresh_name_callback ~pattern)
 ;;