1.1 --- a/src/Tools/isac/Interpret/script.sml	Mon Sep 13 16:36:14 2010 +0200
     1.2 +++ b/src/Tools/isac/Interpret/script.sml	Mon Sep 13 17:21:22 2010 +0200
     1.3 @@ -43,7 +43,7 @@
     1.4     found by next_tac.
     1.5     a leaf is either a tactic or an 'exp' in 'let v = expr'
     1.6     where 'exp' does not contain a tactic.*)   
     1.7 -val trace_script = ref false;
     1.8 +val trace_script = Unsynchronized.ref false;
     1.9  
    1.10  type step =     (*data for creating a new node in the ptree;
    1.11  		 designed for use: