X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fcomponents%2Fng_kernel%2FnCicEnvironment.ml;h=991a88f6406a120b9066d9c28e062ce7ff1aa13b;hb=d51f9674886d1e609a6ea792b65871dcde4f6503;hp=c7389f16761b4d64579a9a3afb013378b3f790e7;hpb=894d518aa760c9f816ddb0dc2b3fa88e1fe20a94;p=helm.git

diff --git a/matita/components/ng_kernel/nCicEnvironment.ml b/matita/components/ng_kernel/nCicEnvironment.ml
index c7389f167..991a88f64 100644
--- a/matita/components/ng_kernel/nCicEnvironment.ml
+++ b/matita/components/ng_kernel/nCicEnvironment.ml
@@ -155,11 +155,11 @@ let typeof_sort = function
   | C.Prop -> (C.Type [])
 ;;
 
-let add_lt_constraint a b = 
+let add_lt_constraint ~acyclic a b = 
   match a,b with
   | [`Type,a2],[`Type,b2] -> 
       if not (lt_path_uri [] a2 b2) then (
-        if lt_path_uri [] b2 a2 || NUri.eq a2 b2 then
+        if acyclic && (lt_path_uri [] b2 a2 || NUri.eq a2 b2) then
          (raise(BadConstraint(lazy("universe inconsistency adding "^
                     pp_constraint a2 b2
            ^ " to:\n" ^ pp_constraints ()))));
@@ -331,12 +331,14 @@ let check_and_add_obj (status:#NCic.status) ((u,_,_,_,_) as obj) =
   | e ->
      frozen_list := saved_frozen_list;
      let exn = `Exn e in
-     NUri.UriHash.add cache u exn;
      history := (`Obj (u,obj))::!history;
      if saved_frozen_list = [] then
       exn
      else
-      raise (Propagate (u,e))
+      begin
+       NUri.UriHash.add cache u exn;
+       raise (Propagate (u,e))
+      end
 ;;
 
 let get_checked_obj status u =