1.1 --- a/src/Tools/isac/calcelems.sml	Sun Feb 25 12:36:23 2018 +0100
     1.2 +++ b/src/Tools/isac/calcelems.sml	Sun Feb 25 14:02:42 2018 +0100
     1.3 @@ -838,6 +838,8 @@
     1.4  fun maxthy thy1 thy2 = if Context.subthy (thy1, thy2) then thy2 else thy1;
     1.5  
     1.6  
     1.7 +(* trace internal steps of isac's numeral calculations *)
     1.8 +val trace_calc = Unsynchronized.ref false;
     1.9  (*.trace internal steps of isac's rewriter*)
    1.10  val trace_rewrite = Unsynchronized.ref false;
    1.11  (*.depth of recursion in traces of the rewriter, if trace_rewrite:=true.*)