X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Focaml%2Fcic_proof_checking%2FcicSubstitution.ml;h=a30a036cb42dc7726c1720906d706f903b0fcf30;hb=f1dc70ca55058b2983cd23b829d856df3b41b9a7;hp=e9ce94eb817e7f669a5bdec6875a869ed490f8d7;hpb=afa05d30f20de12e031c3e5c3e5c33c19c42a7d8;p=helm.git

diff --git a/helm/ocaml/cic_proof_checking/cicSubstitution.ml b/helm/ocaml/cic_proof_checking/cicSubstitution.ml
index e9ce94eb8..a30a036cb 100644
--- a/helm/ocaml/cic_proof_checking/cicSubstitution.ml
+++ b/helm/ocaml/cic_proof_checking/cicSubstitution.ml
@@ -23,6 +23,8 @@
  * http://cs.unibo.it/helm/.
  *)
 
+(* $Id$ *)
+
 exception CannotSubstInMeta;;
 exception RelToHiddenHypothesis;;
 exception ReferenceToVariable;;
@@ -189,7 +191,7 @@ let subst arg =
 (*CSC: dovrebbe diventare da sinistra verso destra:                      *)
 (*CSC: t{a=a/A;b/a} ==> \H:a=a.H{b/a} ==> \H:b=b.H                       *)
 (*CSC: per la roba che proviene da Coq questo non serve!                 *)
-let subst_vars exp_named_subst =
+let subst_vars exp_named_subst t =
 (*
 debug_print (lazy ("@@@POSSIBLE BUG: SUBSTITUTION IS NOT SIMULTANEOUS")) ;
 *)
@@ -342,7 +344,8 @@ if List.mem uri params then debug_print (lazy "---- OK2") ;
    List.map (function (uri,t) -> (uri,substaux k t)) exp_named_subst' @
     (filter_and_lift exp_named_subst)
  in
-  substaux 1
+  if exp_named_subst = [] then t
+  else substaux 1 t
 ;;
 
 (* subst_meta [t_1 ; ... ; t_n] t                                *)