--- a/doc-src/TutorialI/Misc/document/Itrev.tex Sun Jan 21 13:21:14 2001 +0100
+++ b/doc-src/TutorialI/Misc/document/Itrev.tex Sun Jan 21 19:50:43 2001 +0100
@@ -62,8 +62,8 @@
Unfortunately, this is not a complete success:
\begin{isabelle}%
\ {\isadigit{1}}{\isachardot}\ {\isasymAnd}a\ list{\isachardot}\isanewline
-\ \ \ \ \ \ \ itrev\ list\ {\isacharbrackleft}{\isacharbrackright}\ {\isacharequal}\ rev\ list\ {\isasymLongrightarrow}\isanewline
-\ \ \ \ \ \ \ itrev\ list\ {\isacharbrackleft}a{\isacharbrackright}\ {\isacharequal}\ rev\ list\ {\isacharat}\ {\isacharbrackleft}a{\isacharbrackright}%
+\isaindent{\ {\isadigit{1}}{\isachardot}\ \ \ \ }itrev\ list\ {\isacharbrackleft}{\isacharbrackright}\ {\isacharequal}\ rev\ list\ {\isasymLongrightarrow}\isanewline
+\isaindent{\ {\isadigit{1}}{\isachardot}\ \ \ \ }itrev\ list\ {\isacharbrackleft}a{\isacharbrackright}\ {\isacharequal}\ rev\ list\ {\isacharat}\ {\isacharbrackleft}a{\isacharbrackright}%
\end{isabelle}
Just as predicted above, the overall goal, and hence the induction
hypothesis, is too weak to solve the induction step because of the fixed
@@ -89,8 +89,8 @@
not there:
\begin{isabelle}%
\ {\isadigit{1}}{\isachardot}\ {\isasymAnd}a\ list{\isachardot}\isanewline
-\ \ \ \ \ \ \ itrev\ list\ ys\ {\isacharequal}\ rev\ list\ {\isacharat}\ ys\ {\isasymLongrightarrow}\isanewline
-\ \ \ \ \ \ \ itrev\ list\ {\isacharparenleft}a\ {\isacharhash}\ ys{\isacharparenright}\ {\isacharequal}\ rev\ list\ {\isacharat}\ a\ {\isacharhash}\ ys%
+\isaindent{\ {\isadigit{1}}{\isachardot}\ \ \ \ }itrev\ list\ ys\ {\isacharequal}\ rev\ list\ {\isacharat}\ ys\ {\isasymLongrightarrow}\isanewline
+\isaindent{\ {\isadigit{1}}{\isachardot}\ \ \ \ }itrev\ list\ {\isacharparenleft}a\ {\isacharhash}\ ys{\isacharparenright}\ {\isacharequal}\ rev\ list\ {\isacharat}\ a\ {\isacharhash}\ ys%
\end{isabelle}
The induction hypothesis is still too weak, but this time it takes no
intuition to generalize: the problem is that \isa{ys} is fixed throughout