diff -r 14a12da7288e -r 04f905c13502 doc-src/TutorialI/Trie/document/Trie.tex
--- a/doc-src/TutorialI/Trie/document/Trie.tex	Sun Aug 31 21:27:58 2003 +0200
+++ b/doc-src/TutorialI/Trie/document/Trie.tex	Mon Sep 01 15:07:43 2003 +0200
@@ -175,7 +175,7 @@
   Conceptually, each node contains a mapping from letters to optional
   subtries. Above we have implemented this by means of an association
   list. Replay the development replacing \isa{{\isacharparenleft}{\isacharprime}a\ {\isasymtimes}\ {\isacharparenleft}{\isacharprime}a{\isacharcomma}\ {\isacharprime}v{\isacharparenright}\ trie{\isacharparenright}\ list}
-  with \isa{{\isacharprime}a\ {\isasymRightarrow}\ {\isacharparenleft}{\isacharprime}a{\isacharcomma}\ {\isacharprime}v{\isacharparenright}\ trie\ option}.
+  with \isa{{\isacharprime}a\ {\isasymrightharpoonup}\ {\isacharparenleft}{\isacharprime}a{\isacharcomma}\ {\isacharprime}v{\isacharparenright}\ trie}.
 \end{exercise}%
 \end{isamarkuptext}%
 \isamarkuptrue%