
diff -r 0e7b145c3a89 -r 3f2a9f400168 doc-src/TutorialI/Advanced/document/WFrec.tex
--- a/doc-src/TutorialI/Advanced/document/WFrec.tex	Wed May 25 09:03:53 2005 +0200
+++ b/doc-src/TutorialI/Advanced/document/WFrec.tex	Wed May 25 09:04:24 2005 +0200
@@ -85,12 +85,37 @@
 \end{isamarkuptext}%
 \isamarkuptrue%
 \isacommand{lemma}\ wf{\isacharunderscore}greater{\isacharcolon}\ {\isachardoublequote}wf\ {\isacharbraceleft}{\isacharparenleft}i{\isacharcomma}j{\isacharparenright}{\isachardot}\ j{\isacharless}i\ {\isasymand}\ i\ {\isasymle}\ {\isacharparenleft}N{\isacharcolon}{\isacharcolon}nat{\isacharparenright}{\isacharbraceright}{\isachardoublequote}\isamarkupfalse%
-\isamarkuptrue%
-\isamarkupfalse%
+%
+\begin{isamarkuptxt}%
+\noindent
+The proof is by showing that our relation is a subset of another well-founded
+relation: one given by a measure function.\index{*wf_subset (theorem)}%
+\end{isamarkuptxt}%
 \isamarkuptrue%
-\isamarkupfalse%
+\isacommand{apply}\ {\isacharparenleft}rule\ wf{\isacharunderscore}subset\ {\isacharbrackleft}of\ {\isachardoublequote}measure\ {\isacharparenleft}{\isasymlambda}k{\isacharcolon}{\isacharcolon}nat{\isachardot}\ N{\isacharminus}k{\isacharparenright}{\isachardoublequote}{\isacharbrackright}{\isacharcomma}\ blast{\isacharparenright}\isamarkupfalse%
+%
+\begin{isamarkuptxt}%
+\begin{isabelle}%
+\ {\isadigit{1}}{\isachardot}\ {\isacharbraceleft}{\isacharparenleft}i{\isacharcomma}\ j{\isacharparenright}{\isachardot}\ j\ {\isacharless}\ i\ {\isasymand}\ i\ {\isasymle}\ N{\isacharbraceright}\ {\isasymsubseteq}\ measure\ {\isacharparenleft}op\ {\isacharminus}\ N{\isacharparenright}%
+\end{isabelle}
+
+\noindent
+The inclusion remains to be proved. After unfolding some definitions, 
+we are left with simple arithmetic:%
+\end{isamarkuptxt}%
 \isamarkuptrue%
-\isamarkupfalse%
+\isacommand{apply}\ {\isacharparenleft}clarify{\isacharcomma}\ simp\ add{\isacharcolon}\ measure{\isacharunderscore}def\ inv{\isacharunderscore}image{\isacharunderscore}def{\isacharparenright}\isamarkupfalse%
+%
+\begin{isamarkuptxt}%
+\begin{isabelle}%
+\ {\isadigit{1}}{\isachardot}\ {\isasymAnd}a\ b{\isachardot}\ {\isasymlbrakk}b\ {\isacharless}\ a{\isacharsemicolon}\ a\ {\isasymle}\ N{\isasymrbrakk}\ {\isasymLongrightarrow}\ N\ {\isacharminus}\ a\ {\isacharless}\ N\ {\isacharminus}\ b%
+\end{isabelle}
+
+\noindent
+And that is dispatched automatically:%
+\end{isamarkuptxt}%
+\isamarkuptrue%
+\isacommand{by}\ arith\isamarkupfalse%
 %
 \begin{isamarkuptext}%
 \noindent




