* http://cs.unibo.it/helm/.
*)
-exception RefineFailure of string;;
-exception Uncertain of string;;
-exception AssertFailure of string;;
+exception RefineFailure of string Lazy.t;;
+exception Uncertain of string Lazy.t;;
+exception AssertFailure of string Lazy.t;;
(* type_of_aux' metasenv context term graph *)
(* refines [term] and returns the refined form of [term], *)