diff -r 279da0358aa9 -r 09a6c44a48ea doc-src/TutorialI/Advanced/simp.thy
--- a/doc-src/TutorialI/Advanced/simp.thy	Thu Jul 26 18:23:38 2001 +0200
+++ b/doc-src/TutorialI/Advanced/simp.thy	Fri Aug 03 18:04:55 2001 +0200
@@ -45,7 +45,7 @@
 congruence rule for @{text if}. Analogous rules control the evaluation of
 @{text case} expressions.
 
-You can declare your own congruence rules with the attribute @{text cong},
+You can declare your own congruence rules with the attribute \attrdx{cong},
 either globally, in the usual manner,
 \begin{quote}
 \isacommand{declare} \textit{theorem-name} @{text"[cong]"}