diff -r 145e45cd7a0f -r b125dcf14489 src/Tools/isac/MathEngBasic/rewrite.sml
--- a/src/Tools/isac/MathEngBasic/rewrite.sml	Wed Aug 03 17:18:47 2022 +0200
+++ b/src/Tools/isac/MathEngBasic/rewrite.sml	Wed Aug 03 18:06:02 2022 +0200
@@ -50,7 +50,7 @@
 
 exception NO_REWRITE;
 
-(* depth of recursion in traces of the rewriter, if trace_on:=true *)
+(* depth of recursion in traces of the rewriter, if trace_on = true *)
 val rewrite_trace_depth = Attrib.setup_config_int \<^binding>\<open>rewrite_trace_depth\<close> (K 99999);
 
 fun trace ctxt i str =