X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fcomponents%2Fng_paramodulation%2FfoSubst.ml;h=5cb84e1c938d1ff20b359bc738f7f0b713cfe87f;hb=0ef9250d71eacd6b1022194128e6acfb74d52aac;hp=bfef2f2b176d531f385bf782bf1cc9fed0271397;hpb=d6139bbb7c5e20f8139231a90435b8b82a0438ef;p=helm.git

diff --git a/helm/software/components/ng_paramodulation/foSubst.ml b/helm/software/components/ng_paramodulation/foSubst.ml
index bfef2f2b1..5cb84e1c9 100644
--- a/helm/software/components/ng_paramodulation/foSubst.ml
+++ b/helm/software/components/ng_paramodulation/foSubst.ml
@@ -9,22 +9,22 @@
      \ /   This software is distributed as is, NO WARRANTY.     
       V_______________________________________________________________ *)
 
-module Subst (B : Terms.Blob) = struct
+(* module Subst (B : Terms.Blob) = struct *)
   
   let id_subst = [];;
   
   let build_subst n t tail = (n,t) :: tail ;;
   
-  let rec lookup_subst var subst =
+  let rec lookup var subst =
     match var with
       | Terms.Var i ->
           (try
-            lookup_subst (List.assoc i subst) subst
+            lookup (List.assoc i subst) subst
           with
               Not_found -> var)
       | _ -> var
   ;;
-  let lookup_subst i subst = lookup_subst (Terms.Var i) subst;;
+  let lookup i subst = lookup (Terms.Var i) subst;;
   
   let is_in_subst i subst = List.mem_assoc i subst;;
   
@@ -38,11 +38,14 @@ module Subst (B : Terms.Blob) = struct
 
   let rec apply_subst subst = function
     | (Terms.Leaf _) as t -> t
-    | Terms.Var i -> lookup_subst i subst
+    | Terms.Var i -> 
+        (match lookup i subst with
+        | Terms.Node _ as t -> apply_subst subst t
+        | t -> t)
     | (Terms.Node l) ->
 	Terms.Node (List.map (fun t -> apply_subst subst t) l)
 ;;
 
   let concat x y = x @ y;;
   
-end
+(* end *)