From d05c85b6f240e7e919b4be71896df8310f088589 Mon Sep 17 00:00:00 2001
From: Claudio Sacerdoti Coen <claudio.sacerdoticoen@unibo.it>
Date: Sun, 17 May 2009 19:13:21 +0000
Subject: [PATCH] maxmeta implemented

---
 .../components/ng_refiner/nCicMetaSubst.ml    | 33 ++++++++++++-------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/helm/software/components/ng_refiner/nCicMetaSubst.ml b/helm/software/components/ng_refiner/nCicMetaSubst.ml
index 432f3e4bf..26dc85cac 100644
--- 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;;
@@ -245,7 +246,7 @@ 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 +256,23 @@ 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 +403,10 @@ 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 +425,7 @@ 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
-- 
2.39.2