diff -r 0b231e0fd7d7 -r 54e2f4c8c3cb doc-src/ttbox.sty
--- a/doc-src/ttbox.sty	Fri Sep 28 16:42:26 2001 +0200
+++ b/doc-src/ttbox.sty	Fri Sep 28 16:42:58 2001 +0200
@@ -32,6 +32,8 @@
 \chardef\ttback=`\\     % A backslash for \tt font
 \chardef\ttlbrace=`\{   % A left brace for \tt font
 \chardef\ttrbrace=`\}   % A right brace for \tt font
+\chardef\ttlbrack=`\[   % A left bracket for \tt font
+\chardef\ttrbrack=`\]   % A right bracket for \tt font
 
 \newcommand\out{\ \ttfamily\slshape}   %% for output from terminal sessions