[re.def] Clarify index entry for "sub-expression"

tkoeppe · tkoeppe · commit bfcc4d844ac3 · 2017-12-06T22:01:32.000Z
diff --git a/source/regex.tex b/source/regex.tex
@@ -76,7 +76,7 @@
 a pattern that selects specific strings
 from a set of character strings.
 
-\indextext{sub-expression}%
+\indextext{sub-expression!regular expression}%
 \definition{sub-expression}{defns.regex.subexpression}
 a subset of a regular expression that has
 been marked by parenthesis.
