X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fcomponents%2Fng_refiner%2FnCicUnification.ml;h=c7b487461963a179bd6333232cefb7ce13385bbf;hb=a90c31c1b53222bd6d57360c5ba5c2d0fe7d5207;hp=fcc76b0adc5bf72b38129bd36a3ddca7952d4676;hpb=4377e950998c9c63937582952a79975947aa9a45;p=helm.git

diff --git a/helm/software/components/ng_refiner/nCicUnification.ml b/helm/software/components/ng_refiner/nCicUnification.ml
index fcc76b0ad..c7b487461 100644
--- a/helm/software/components/ng_refiner/nCicUnification.ml
+++ b/helm/software/components/ng_refiner/nCicUnification.ml
@@ -50,7 +50,7 @@ let eta_reduce subst t =
           let _,_,t,_ = NCicUtils.lookup_subst i subst in
           let t = NCicSubstitution.subst_meta lc t in
           eat_lambdas ctx t
-        with NCicUtils.Subst_not_found _ -> ctx, t)
+        with Not_found -> ctx, t)
     | t -> ctx, t
   in
   let context_body = eat_lambdas [] t in
@@ -97,7 +97,7 @@ let outside exc_opt =
    let time2 = Unix.gettimeofday () in
    let time1 =
     match !times with time1::tl -> times := tl; time1 | [] -> assert false in
-   prerr_endline ("}}} " ^ !indent ^ " " ^ string_of_float (time2 -. time1));
+   prerr_endline ("}}} " ^ string_of_float (time2 -. time1));
    (match exc_opt with
    | Some e ->  prerr_endline ("exception raised: " ^ Printexc.to_string e)
    | None -> ());
@@ -382,8 +382,8 @@ let rec instantiate rdb test_eq_only metasenv subst context n lc t swap =
        | _ ->
         let lty = NCicSubstitution.subst_meta lc ty in
         pp (lazy ("On the types: " ^
-          ppterm ~metasenv ~subst ~context ty_t ^ "=<=" ^
-          ppterm ~metasenv ~subst ~context lty)); 
+          ppterm ~metasenv ~subst ~context lty ^ "=<=" ^
+          ppterm ~metasenv ~subst ~context ty_t)); 
         let metasenv, subst = 
           unify rdb false metasenv subst context ty_t lty false
         in
@@ -559,17 +559,6 @@ and unify rdb test_eq_only metasenv subst context t1 t2 swap =
               len2 < len1 && cc2 = fst (HExtlib.split_nth len2 cc1) ->
           instantiate rdb test_eq_only metasenv subst context m lc'
             (NCicReduction.head_beta_reduce ~subst t1) (not swap)
-       | C.Meta (n,lc), C.Meta (m,lc') when
-          let _,_,tyn = NCicUtils.lookup_meta n metasenv in
-          let _,_,tym = NCicUtils.lookup_meta m metasenv in
-          let tyn = NCicSubstitution.subst_meta lc tyn in
-          let tym = NCicSubstitution.subst_meta lc tym in
-           match tyn,tym with
-              NCic.Sort NCic.Type u1, NCic.Sort NCic.Type u2 ->
-               NCicEnvironment.universe_lt u1 u2
-            | _,_ -> false ->
-          instantiate rdb test_eq_only metasenv subst context m lc'
-            (NCicReduction.head_beta_reduce ~subst t1) (not swap)
        | C.Meta (n,lc), t -> 
           instantiate rdb test_eq_only metasenv subst context n lc 
             (NCicReduction.head_beta_reduce ~subst t) swap
@@ -577,62 +566,28 @@ and unify rdb test_eq_only metasenv subst context t1 t2 swap =
           instantiate rdb test_eq_only metasenv subst context n lc 
            (NCicReduction.head_beta_reduce ~subst t) (not swap)
 
-       (* higher order unification case *)
        | NCic.Appl (NCic.Meta (i,l) as meta :: args), _ ->
-           (* this easy_case handles "(? ?) =?= (f a)", same number of 
-            * args, preferring the instantiation "f" over "\_.f a" for the
-            * metavariable in head position. Since the arguments of the meta
-            * are flexible, delift would ignore them generating a constant
-            * function even in the easy case above *)
-           let easy_case = 
-             match t2 with
-             | NCic.Appl (f :: f_args)
-               when 
-               List.exists (NCicMetaSubst.is_flexible context ~subst) args ->
-                let mlen = List.length args in
-                let flen = List.length f_args in
-                let min_len = min mlen flen in
-                let mhe,margs = HExtlib.split_nth (mlen - min_len) args in
-                let fhe,fargs = HExtlib.split_nth (flen - min_len) f_args in
-                 (try 
-                    Some (List.fold_left2 
-                      (fun (m, s) t1 t2 -> 
-                        unify rdb test_eq_only m s context t1 t2 swap
-                      ) (metasenv,subst)
-                        ((NCicUntrusted.mk_appl meta mhe)::margs)
-                        ((NCicUntrusted.mk_appl f fhe)::fargs))
-                  with UnificationFailure _ | Uncertain _ | KeepReducing _ ->
-                    None) 
-             | _ -> None
-           in
-           (match easy_case with
-           | Some ms -> ms
-           | None ->
-               (* This case handles "(?_f ..ti..) =?= t2", abstracting every
-                * non flexible ti (delift skips local context items that are
-                * flexible) from t2 in two steps:
-                *  1) ?_f := \..xi.. .?
-                *  2) ?_f ..ti..  =?= t2 --unif_machines-->
-                      ?_f[..ti..] =?= t2 --instantiate-->
-                      delift [..ti..] t2 *)
-               let metasenv, lambda_Mj =
-                 lambda_intros rdb metasenv subst context (List.length args)
-                  (NCicTypeChecker.typeof ~metasenv ~subst context meta)
-               in
-               let metasenv, subst = 
-                 unify rdb test_eq_only metasenv subst context 
-                   (C.Meta (i,l)) lambda_Mj swap
-               in
-               let metasenv, subst = 
-                 unify rdb test_eq_only metasenv subst context t1 t2 swap
-               in
-               (try
-                 let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
-                 let term = eta_reduce subst term in
-                 let subst = List.filter (fun (j,_) -> j <> i) subst in
-                 metasenv, ((i, (name, ctx, term, ty)) :: subst)
-               with Not_found -> assert false))
-
+          let metasenv, lambda_Mj =
+            lambda_intros rdb metasenv subst context (List.length args)
+             (NCicTypeChecker.typeof ~metasenv ~subst context meta)
+          in
+          let metasenv, subst = 
+           try
+            unify rdb test_eq_only metasenv subst context 
+              (C.Meta (i,l)) lambda_Mj swap
+           with UnificationFailure msg | Uncertain msg when not norm2->
+            (* failure: let's try again argument vs argument *)
+            raise (KeepReducing msg)
+          in
+          let metasenv, subst = 
+            unify rdb test_eq_only metasenv subst context t1 t2 swap
+          in
+          (try
+            let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
+            let term = eta_reduce subst term in
+            let subst = List.filter (fun (j,_) -> j <> i) subst in
+            metasenv, ((i, (name, ctx, term, ty)) :: subst)
+          with Not_found -> assert false)
        | _, NCic.Appl (NCic.Meta (_,_) :: _) ->
            unify rdb test_eq_only metasenv subst context t2 t1 (not swap)
 
@@ -657,12 +612,14 @@ and unify rdb test_eq_only metasenv subst context t1 t2 swap =
              with
                 Invalid_argument _ -> 
                  raise (Uncertain (mk_msg metasenv subst context t1 t2))
+              | UnificationFailure _ | Uncertain _ when not (norm1 && norm2) ->
+                 raise (KeepReducing (mk_msg metasenv subst context t1 t2))
               | KeepReducing _ | KeepReducingThis _ -> assert false
            in 
              metasenv, subst
 
        | (C.Match (Ref.Ref (_,Ref.Ind (_,tyno,_)) as ref1,outtype1,term1,pl1),
-          C.Match (ref2,outtype2,term2,pl2)) when Ref.eq ref1 ref2 ->
+          C.Match (ref2,outtype2,term2,pl2)) ->
            let _,_,itl,_,_ = NCicEnvironment.get_checked_indtys ref1 in
            let _,_,ty,_ = List.nth itl tyno in
            let rec remove_prods ~subst context ty = 
@@ -678,9 +635,9 @@ and unify rdb test_eq_only metasenv subst context t1 t2 swap =
              | C.Sort C.Prop -> true
              | _ -> false 
            in
-           (* if not (Ref.eq ref1 ref2) then 
+           if not (Ref.eq ref1 ref2) then 
              raise (Uncertain (mk_msg metasenv subst context t1 t2))
-           else*)
+           else
              let metasenv, subst = 
               unify rdb test_eq_only metasenv subst context outtype1 outtype2 swap in
              let metasenv, subst = 
@@ -703,17 +660,7 @@ and unify rdb test_eq_only metasenv subst context t1 t2 swap =
        | _ -> raise (KeepReducing (mk_msg metasenv subst context t1 t2))
      (*D*)  in outside None; rc with exn -> outside (Some exn); raise exn 
     in
-    let fo_unif test_eq_only metasenv subst (norm1,t1 as nt1) (norm2,t2 as nt2)=
-     try fo_unif test_eq_only metasenv subst nt1 nt2
-     with
-      UnificationFailure _ | Uncertain _ when not norm1 || not norm2 ->
-       raise (KeepReducing (mk_msg metasenv subst context t1 t2))
-    in
     let try_hints metasenv subst (_,t1 as mt1) (_,t2 as mt2) (* exc*) =
-      if NCicUntrusted.metas_of_term subst context t1 = [] &&
-         NCicUntrusted.metas_of_term subst context t2 = [] 
-      then None 
-      else begin
     (*D*) inside 'H'; try let rc =  
      pp(lazy ("\nProblema:\n" ^
         ppterm ~metasenv ~subst ~context t1 ^ " =?= " ^
@@ -743,7 +690,7 @@ and unify rdb test_eq_only metasenv subst context t1 t2 swap =
                 List.fold_left 
                   (fun (metasenv, subst) (x,y) ->
                      unify rdb test_eq_only metasenv subst context x y false)
-                  (metasenv, subst) (List.rev premises)
+                  (metasenv, subst) premises
               in
               pp(lazy("FUNZIONA!"));
               Some (metasenv, subst)
@@ -754,7 +701,6 @@ and unify rdb test_eq_only metasenv subst context t1 t2 swap =
       in
         cand_iter candidates
      (*D*)  in outside None; rc with exn -> outside (Some exn); raise exn 
-      end
     in
     let put_in_whd m1 m2 =
       NCicReduction.reduce_machine ~delta:max_int ~subst context m1,
@@ -779,32 +725,6 @@ and unify rdb test_eq_only metasenv subst context t1 t2 swap =
               | Uncertain _ as exn -> raise exn
               | _ -> assert false
     in
-    let fo_unif_heads_and_cont_or_unwind_and_hints 
-      test_eq_only metasenv subst m1 m2 cont hm1 hm2
-     =
-      let ms, continuation = 
-        (* calling the continuation inside the outermost try is an option
-           and makes unification stronger, but looks not frequent to me
-           that heads unify but not the arguments and that an hints can fix 
-           that *)
-        try fo_unif test_eq_only metasenv subst m1 m2, cont
-        with 
-        | UnificationFailure _ 
-        | KeepReducing _ | Uncertain _ as exn ->
-           let (t1,norm1),(t2,norm2) = hm1, hm2 in
-           match 
-             try_hints metasenv subst 
-              (norm1,NCicReduction.unwind t1) (norm2,NCicReduction.unwind t2)
-           with
-            | Some x -> x, fun x -> x
-            | None -> 
-                match exn with 
-                | KeepReducing msg -> raise (KeepReducingThis (msg,hm1,hm2))
-                | UnificationFailure _ | Uncertain _ as exn -> raise exn
-                | _ -> assert false
-      in
-        continuation ms
-    in
     let height_of = function
      | NCic.Const (Ref.Ref (_,Ref.Def h)) 
      | NCic.Const (Ref.Ref (_,Ref.Fix (_,_,h))) 
@@ -842,7 +762,7 @@ and unify rdb test_eq_only metasenv subst context t1 t2 swap =
             match t1 with
             | C.Const r -> NCicEnvironment.get_relevance r
             | _ -> [] *) in
-          let unif_from_stack (metasenv, subst) (t1, t2, b) =
+          let unif_from_stack t1 t2 b metasenv subst =
               try
                 let t1 = NCicReduction.from_stack ~delta:max_int t1 in
                 let t2 = NCicReduction.from_stack ~delta:max_int t2 in
@@ -859,24 +779,19 @@ and unify rdb test_eq_only metasenv subst context t1 t2 swap =
                 NCicReduction.unwind (k2,e2,t2,List.rev l2),
                 todo
           in
-          let check_stack l1 l2 r =
-            match t1, t2 with
-            | NCic.Meta _, _ | _, NCic.Meta _ ->
-                (NCicReduction.unwind (k1,e1,t1,s1)),
-                (NCicReduction.unwind (k2,e2,t2,s2)),[]     
-            | _ -> check_stack l1 l2 r []
-          in
-        let hh1,hh2,todo = check_stack (List.rev s1) (List.rev s2) relevance in
+        let hh1,hh2,todo=check_stack (List.rev s1) (List.rev s2) relevance [] in
         try
-          fo_unif_heads_and_cont_or_unwind_and_hints
-            test_eq_only metasenv subst (norm1,hh1) (norm2,hh2) 
-            (fun ms -> List.fold_left unif_from_stack ms todo)
-            m1 m2
+         let metasenv,subst =
+          fo_unif_w_hints test_eq_only metasenv subst (norm1,hh1) (norm2,hh2) in
+         List.fold_left
+          (fun (metasenv,subst) (x1,x2,r) ->
+            unif_from_stack x1 x2 r metasenv subst
+          ) (metasenv,subst) todo
         with
          | KeepReducing _ -> assert false
          | KeepReducingThis _ ->
             assert (not (norm1 && norm2));
-            unif_machines metasenv subst (small_delta_step ~subst m1 m2)
+	    unif_machines metasenv subst (small_delta_step ~subst m1 m2)
          | UnificationFailure _ | Uncertain _ when (not (norm1 && norm2))
            -> unif_machines metasenv subst (small_delta_step ~subst m1 m2)
          | UnificationFailure msg