diff -r 12875677300b -r 8223e7f4b0da src/HOL/Tools/Predicate_Compile/code_prolog.ML
--- a/src/HOL/Tools/Predicate_Compile/code_prolog.ML	Sat Mar 26 19:16:30 2011 +0100
+++ b/src/HOL/Tools/Predicate_Compile/code_prolog.ML	Sat Mar 26 18:31:39 2011 +0100
@@ -857,7 +857,7 @@
     val prog = prelude system ^ query system nsols (query_rel, args') vnames' ^ write_program p
     val _ = tracing ("Generated prolog program:\n" ^ prog)
     val solution = TimeLimit.timeLimit timeout (fn prog =>
-      Isabelle_System.with_tmp_file "prolog_file" (fn prolog_file =>
+      Isabelle_System.with_tmp_file "prolog_file" "" (fn prolog_file =>
         (File.write prolog_file prog; invoke system prolog_file))) prog
     val _ = tracing ("Prolog returned solution(s):\n" ^ solution)
     val tss = parse_solutions solution