diff -r 9be481b4bc85 -r 699de91b15e2 doc-src/TutorialI/Misc/document/Tree.tex
--- a/doc-src/TutorialI/Misc/document/Tree.tex	Tue Aug 29 00:57:24 2000 +0200
+++ b/doc-src/TutorialI/Misc/document/Tree.tex	Tue Aug 29 11:52:16 2000 +0200
@@ -1,4 +1,5 @@
-\begin{isabelle}%
+%
+\begin{isabellebody}%
 %
 \begin{isamarkuptext}%
 \noindent
@@ -16,7 +17,7 @@
 Define a function \isa{flatten} that flattens a tree into a list
 by traversing it in infix order. Prove%
 \end{isamarkuptext}%
-\isacommand{lemma}\ {\isachardoublequote}flatten{\isacharparenleft}mirror\ t{\isacharparenright}\ {\isacharequal}\ rev{\isacharparenleft}flatten\ t{\isacharparenright}{\isachardoublequote}\end{isabelle}%
+\isacommand{lemma}\ {\isachardoublequote}flatten{\isacharparenleft}mirror\ t{\isacharparenright}\ {\isacharequal}\ rev{\isacharparenleft}flatten\ t{\isacharparenright}{\isachardoublequote}\end{isabellebody}%
 %%% Local Variables:
 %%% mode: latex
 %%% TeX-master: "root"