diff -r 7e51c9f3d5a0 -r a5f86aed785b doc-src/TutorialI/Trie/document/Option2.tex
--- a/doc-src/TutorialI/Trie/document/Option2.tex	Tue Aug 29 15:13:10 2000 +0200
+++ b/doc-src/TutorialI/Trie/document/Option2.tex	Tue Aug 29 15:43:29 2000 +0200
@@ -1,6 +1,7 @@
-\begin{isabelle}%
+%
+\begin{isabellebody}%
 \isanewline
-\isacommand{datatype}\ {\isacharprime}a\ option\ {\isacharequal}\ None\ {\isacharbar}\ Some\ {\isacharprime}a\end{isabelle}%
+\isacommand{datatype}\ {\isacharprime}a\ option\ {\isacharequal}\ None\ {\isacharbar}\ Some\ {\isacharprime}a\end{isabellebody}%
 %%% Local Variables:
 %%% mode: latex
 %%% TeX-master: "root"