Let's refresh the universe to avoid assert failure.

[helm.git] / helm / software / components / ng_refiner / nCicMetaSubst.ml

diff --git a/helm/software/components/ng_refiner/nCicMetaSubst.ml b/helm/software/components/ng_refiner/nCicMetaSubst.ml
index 432f3e4bf064786df54d371ddaefdf140f73dac5..9cc6ac67c755c16e4208413f1cd7565859c64557 100644 (file)
--- a/helm/software/components/ng_refiner/nCicMetaSubst.ml
+++ b/helm/software/components/ng_refiner/nCicMetaSubst.ml
@@ -14,9 +14,10 @@
 exception MetaSubstFailure of string Lazy.t
 exception Uncertain of string Lazy.t
 
-let newmeta = 
+let newmeta,maxmeta = 
   let maxmeta = ref 0 in
-  fun () -> incr maxmeta; !maxmeta
+  (fun () -> incr maxmeta; !maxmeta),
+  (fun () -> !maxmeta)
 ;;
 
 exception NotInTheList;;
@@ -71,31 +72,41 @@ let rec force_does_not_occur metasenv subst restrictions t =
         in
         if amount > 0 then ms, NCic.Rel (r - amount) else ms, orig
     | NCic.Meta (n, (shift,lc as l)) as orig ->
-       (* we ignore the subst since restrict will take care of already
-        * instantiated/restricted metavariabels *)
-       let (metasenv,subst as ms), restrictions_for_n, l' =
-         let l = NCicUtils.expand_local_context lc in
-
-         let ms, _, restrictions_for_n, l =
-          List.fold_right
-            (fun t (ms, i, restrictions_for_n, l) ->
-              try 
-                let ms, t = aux (k-shift) ms t in
-                ms, i-1, restrictions_for_n, t::l
-              with Occur ->
-                ms, i-1, i::restrictions_for_n, l)
-            l (ms, List.length l, [], [])
-         in
-             
-          ms, restrictions_for_n, pack_lc (shift, NCic.Ctx l)
+       let meta_chain =
+        try
+         Some (NCicUtils.lookup_subst n subst)
+        with
+         NCicUtils.Subst_not_found _ -> None
        in
-       if restrictions_for_n = [] then
-         ms, if l = l' then orig else NCic.Meta (n, l')
-       else
-         let metasenv, subst, newmeta = 
-           restrict metasenv subst n restrictions_for_n 
-         in
-           (metasenv, subst), NCic.Meta (newmeta, l')
+        (match meta_chain with
+            Some (_,_,bo,_) ->
+             aux k ms (NCicSubstitution.subst_meta l bo)
+          | None ->
+             (* we ignore the subst since restrict will take care of already
+              * instantiated/restricted metavariabels *)
+             let (metasenv,subst as ms), restrictions_for_n, l' =
+               let l = NCicUtils.expand_local_context lc in
+         
+               let ms, _, restrictions_for_n, l =
+                List.fold_right
+                  (fun t (ms, i, restrictions_for_n, l) ->
+                    try 
+                      let ms, t = aux (k-shift) ms t in
+                      ms, i-1, restrictions_for_n, t::l
+                    with Occur ->
+                      ms, i-1, i::restrictions_for_n, l)
+                  l (ms, List.length l, [], [])
+               in
+                   
+                ms, restrictions_for_n, pack_lc (shift, NCic.Ctx l)
+             in
+             if restrictions_for_n = [] then
+               ms, if l = l' then orig else NCic.Meta (n, l')
+             else
+               let metasenv, subst, newmeta = 
+                 restrict metasenv subst n restrictions_for_n 
+               in
+                 (metasenv, subst), NCic.Meta (newmeta, l'))
     | t -> NCicUntrusted.map_term_fold_a (fun _ k -> k+1) k aux ms t
  in
    aux 0 (metasenv,subst) t 
@@ -204,8 +215,6 @@ let rec flexible_arg subst = function
   | _ -> false
 ;;
 
-let flexible subst l = List.exists (flexible_arg subst) l;;
-
 let in_scope_tag  = "tag:in_scope" ;;
 let out_scope_tag_prefix = "tag:out_scope:" 
 let out_scope_tag n = out_scope_tag_prefix ^ string_of_int n ;;
@@ -245,7 +254,7 @@ let delift ~unify metasenv subst context n l t =
     in
     try aux () () t; false with Found -> true
   in
-  let unify_list in_scope = 
+  let unify_list ~alpha in_scope = 
     match l with
     | _, NCic.Irl _ -> fun _ _ _ _ _ -> None
     | shift, NCic.Ctx l -> fun metasenv subst context k t ->
@@ -255,16 +264,23 @@ let delift ~unify metasenv subst context n l t =
           (fun (li,flexible) i ->
             if flexible || i < in_scope then None else
              let li = NCicSubstitution.lift (k+shift) li in
-             match unify metasenv subst context li t with
-             | Some (metasenv,subst) -> 
-                 Some ((metasenv, subst), NCic.Rel (i+1+k))
-             | None -> None)
+              if alpha then
+               if NCicReduction.alpha_eq metasenv subst context li t then
+                Some ((metasenv,subst), NCic.Rel (i+1+k))
+               else
+                None
+              else
+               match unify metasenv subst context li t with
+               | Some (metasenv,subst) -> 
+                   Some ((metasenv, subst), NCic.Rel (i+1+k))
+               | None -> None)
           lb
   in
   let rec aux (context,k,in_scope) (metasenv, subst as ms) t = 
-   match unify_list in_scope metasenv subst context k t with
+   match unify_list ~alpha:true in_scope metasenv subst context k t with
    | Some x -> x
    | None -> 
+   try
     match t with 
     | NCic.Rel n as t when n <= k -> ms, t
     | NCic.Rel n -> 
@@ -395,6 +411,10 @@ let delift ~unify metasenv subst context n l t =
     | t -> 
         NCicUntrusted.map_term_fold_a 
           (fun e (c,k,s) -> (e::c,k+1,s)) (context,k,in_scope) aux ms t
+   with NotInTheList ->
+    match unify_list ~alpha:false in_scope metasenv subst context k t with
+    | Some x -> x
+    | None -> raise NotInTheList
   in
    try aux (context,0,0) (metasenv,subst) t
    with NotInTheList ->
@@ -413,10 +433,7 @@ let delift ~unify metasenv subst context n l t =
       let lc = NCicUtils.expand_local_context lc in
       let l = List.map (NCicSubstitution.lift shift) lc in
        if
-         List.exists
-          (fun t -> 
-                  NCicUntrusted.metas_of_term subst context t = [])
-            l
+        List.exists (fun t-> NCicUntrusted.metas_of_term subst context t <> [])l
        then
         raise (Uncertain msg)
        else