src/Tools/try.ML

--- a/src/Tools/try.ML	Wed May 15 22:02:51 2013 +0200
+++ b/src/Tools/try.ML	Wed May 15 22:30:24 2013 +0200
@@ -36,6 +36,7 @@
 
 val _ =
   ProofGeneral.preference_real ProofGeneral.category_tracing
+    NONE
     auto_time_limit
     "auto-try-time-limit"
     "Time limit for automatically tried tools (in seconds)"