src/HOL/Tools/Predicate_Compile/code_prolog.ML
changeset 43324 2b47822868e4
parent 42489 db9b9e46131c
child 43735 9b88fd07b912
--- a/src/HOL/Tools/Predicate_Compile/code_prolog.ML	Thu Jun 09 15:38:49 2011 +0200
+++ b/src/HOL/Tools/Predicate_Compile/code_prolog.ML	Thu Jun 09 16:34:49 2011 +0200
@@ -205,7 +205,7 @@
       (filter (fn s => Symbol.is_ascii_letter s orelse Symbol.is_ascii_digit s)
         (Symbol.explode name)))
     val name'' = f (if name' = "" then empty else name')
-  in (if member (op =) avoid name'' then Name.variant avoid name'' else name'') end
+  in if member (op =) avoid name'' then singleton (Name.variant_list avoid) name'' else name'' end
 
 (** constant table **)