diff -r 0e7b145c3a89 -r 3f2a9f400168 doc-src/TutorialI/Inductive/document/Even.tex --- a/doc-src/TutorialI/Inductive/document/Even.tex Wed May 25 09:03:53 2005 +0200 +++ b/doc-src/TutorialI/Inductive/document/Even.tex Wed May 25 09:04:24 2005 +0200 @@ -35,10 +35,22 @@ \isamarkuptrue% \isacommand{lemma}\ two{\isacharunderscore}times{\isacharunderscore}even{\isacharbrackleft}intro{\isacharbang}{\isacharbrackright}{\isacharcolon}\ {\isachardoublequote}{\isadigit{2}}{\isacharasterisk}k\ {\isasymin}\ even{\isachardoublequote}\isanewline \isamarkupfalse% +\isacommand{apply}\ {\isacharparenleft}induct{\isacharunderscore}tac\ k{\isacharparenright}\isamarkupfalse% +% +\begin{isamarkuptxt}% +The first step is induction on the natural number \isa{k}, which leaves +two subgoals: +\begin{isabelle}% +\ {\isadigit{1}}{\isachardot}\ {\isadigit{2}}\ {\isacharasterisk}\ {\isadigit{0}}\ {\isasymin}\ Even{\isachardot}even\isanewline +\ {\isadigit{2}}{\isachardot}\ {\isasymAnd}n{\isachardot}\ {\isadigit{2}}\ {\isacharasterisk}\ n\ {\isasymin}\ Even{\isachardot}even\ {\isasymLongrightarrow}\ {\isadigit{2}}\ {\isacharasterisk}\ Suc\ n\ {\isasymin}\ Even{\isachardot}even% +\end{isabelle} +Here \isa{auto} simplifies both subgoals so that they match the introduction +rules, which then are applied automatically.% +\end{isamarkuptxt}% +\ \isamarkuptrue% +\isacommand{apply}\ auto\isanewline \isamarkupfalse% -\isamarkuptrue% -\isamarkupfalse% -\isamarkupfalse% +\isacommand{done}\isamarkupfalse% % \begin{isamarkuptext}% Our goal is to prove the equivalence between the traditional definition @@ -49,7 +61,7 @@ \isamarkuptrue% \isacommand{lemma}\ dvd{\isacharunderscore}imp{\isacharunderscore}even{\isacharcolon}\ {\isachardoublequote}{\isadigit{2}}\ dvd\ n\ {\isasymLongrightarrow}\ n\ {\isasymin}\ even{\isachardoublequote}\isanewline \isamarkupfalse% -\isamarkupfalse% +\isacommand{by}\ {\isacharparenleft}auto\ simp\ add{\isacharcolon}\ dvd{\isacharunderscore}def{\isacharparenright}\isamarkupfalse% % \begin{isamarkuptext}% our first rule induction!% @@ -57,14 +69,34 @@ \isamarkuptrue% \isacommand{lemma}\ even{\isacharunderscore}imp{\isacharunderscore}dvd{\isacharcolon}\ {\isachardoublequote}n\ {\isasymin}\ even\ {\isasymLongrightarrow}\ {\isadigit{2}}\ dvd\ n{\isachardoublequote}\isanewline \isamarkupfalse% -\isamarkupfalse% -\isamarkuptrue% -\isamarkupfalse% +\isacommand{apply}\ {\isacharparenleft}erule\ even{\isachardot}induct{\isacharparenright}\isamarkupfalse% +% +\begin{isamarkuptxt}% +\begin{isabelle}% +\ {\isadigit{1}}{\isachardot}\ {\isadigit{2}}\ dvd\ {\isadigit{0}}\isanewline +\ {\isadigit{2}}{\isachardot}\ {\isasymAnd}n{\isachardot}\ {\isasymlbrakk}n\ {\isasymin}\ Even{\isachardot}even{\isacharsemicolon}\ {\isadigit{2}}\ dvd\ n{\isasymrbrakk}\ {\isasymLongrightarrow}\ {\isadigit{2}}\ dvd\ Suc\ {\isacharparenleft}Suc\ n{\isacharparenright}% +\end{isabelle}% +\end{isamarkuptxt}% \isamarkuptrue% -\isamarkupfalse% +\isacommand{apply}\ {\isacharparenleft}simp{\isacharunderscore}all\ add{\isacharcolon}\ dvd{\isacharunderscore}def{\isacharparenright}\isamarkupfalse% +% +\begin{isamarkuptxt}% +\begin{isabelle}% +\ {\isadigit{1}}{\isachardot}\ {\isasymAnd}n{\isachardot}\ {\isasymlbrakk}n\ {\isasymin}\ Even{\isachardot}even{\isacharsemicolon}\ {\isasymexists}k{\isachardot}\ n\ {\isacharequal}\ {\isadigit{2}}\ {\isacharasterisk}\ k{\isasymrbrakk}\ {\isasymLongrightarrow}\ {\isasymexists}k{\isachardot}\ Suc\ {\isacharparenleft}Suc\ n{\isacharparenright}\ {\isacharequal}\ {\isadigit{2}}\ {\isacharasterisk}\ k% +\end{isabelle}% +\end{isamarkuptxt}% \isamarkuptrue% +\isacommand{apply}\ clarify\isamarkupfalse% +% +\begin{isamarkuptxt}% +\begin{isabelle}% +\ {\isadigit{1}}{\isachardot}\ {\isasymAnd}n\ k{\isachardot}\ {\isadigit{2}}\ {\isacharasterisk}\ k\ {\isasymin}\ Even{\isachardot}even\ {\isasymLongrightarrow}\ {\isasymexists}ka{\isachardot}\ Suc\ {\isacharparenleft}Suc\ {\isacharparenleft}{\isadigit{2}}\ {\isacharasterisk}\ k{\isacharparenright}{\isacharparenright}\ {\isacharequal}\ {\isadigit{2}}\ {\isacharasterisk}\ ka% +\end{isabelle}% +\end{isamarkuptxt}% +\isamarkuptrue% +\isacommand{apply}\ {\isacharparenleft}rule{\isacharunderscore}tac\ x\ {\isacharequal}\ {\isachardoublequote}Suc\ k{\isachardoublequote}\ \isakeyword{in}\ exI{\isacharcomma}\ simp{\isacharparenright}\isanewline \isamarkupfalse% -\isamarkupfalse% +\isacommand{done}\isamarkupfalse% % \begin{isamarkuptext}% no iff-attribute because we don't always want to use it% @@ -72,7 +104,7 @@ \isamarkuptrue% \isacommand{theorem}\ even{\isacharunderscore}iff{\isacharunderscore}dvd{\isacharcolon}\ {\isachardoublequote}{\isacharparenleft}n\ {\isasymin}\ even{\isacharparenright}\ {\isacharequal}\ {\isacharparenleft}{\isadigit{2}}\ dvd\ n{\isacharparenright}{\isachardoublequote}\isanewline \isamarkupfalse% -\isamarkupfalse% +\isacommand{by}\ {\isacharparenleft}blast\ intro{\isacharcolon}\ dvd{\isacharunderscore}imp{\isacharunderscore}even\ even{\isacharunderscore}imp{\isacharunderscore}dvd{\isacharparenright}\isamarkupfalse% % \begin{isamarkuptext}% this result ISN'T inductive...% @@ -80,9 +112,16 @@ \isamarkuptrue% \isacommand{lemma}\ Suc{\isacharunderscore}Suc{\isacharunderscore}even{\isacharunderscore}imp{\isacharunderscore}even{\isacharcolon}\ {\isachardoublequote}Suc\ {\isacharparenleft}Suc\ n{\isacharparenright}\ {\isasymin}\ even\ {\isasymLongrightarrow}\ n\ {\isasymin}\ even{\isachardoublequote}\isanewline \isamarkupfalse% -\isamarkupfalse% +\isacommand{apply}\ {\isacharparenleft}erule\ even{\isachardot}induct{\isacharparenright}\isamarkupfalse% +% +\begin{isamarkuptxt}% +\begin{isabelle}% +\ {\isadigit{1}}{\isachardot}\ n\ {\isasymin}\ Even{\isachardot}even\isanewline +\ {\isadigit{2}}{\isachardot}\ {\isasymAnd}na{\isachardot}\ {\isasymlbrakk}na\ {\isasymin}\ Even{\isachardot}even{\isacharsemicolon}\ n\ {\isasymin}\ Even{\isachardot}even{\isasymrbrakk}\ {\isasymLongrightarrow}\ n\ {\isasymin}\ Even{\isachardot}even% +\end{isabelle}% +\end{isamarkuptxt}% \isamarkuptrue% -\isamarkupfalse% +\isacommand{oops}\isamarkupfalse% % \begin{isamarkuptext}% ...so we need an inductive lemma...% @@ -90,10 +129,19 @@ \isamarkuptrue% \isacommand{lemma}\ even{\isacharunderscore}imp{\isacharunderscore}even{\isacharunderscore}minus{\isacharunderscore}{\isadigit{2}}{\isacharcolon}\ {\isachardoublequote}n\ {\isasymin}\ even\ {\isasymLongrightarrow}\ n\ {\isacharminus}\ {\isadigit{2}}\ {\isasymin}\ even{\isachardoublequote}\isanewline \isamarkupfalse% -\isamarkupfalse% +\isacommand{apply}\ {\isacharparenleft}erule\ even{\isachardot}induct{\isacharparenright}\isamarkupfalse% +% +\begin{isamarkuptxt}% +\begin{isabelle}% +\ {\isadigit{1}}{\isachardot}\ {\isadigit{0}}\ {\isacharminus}\ {\isadigit{2}}\ {\isasymin}\ Even{\isachardot}even\isanewline +\ {\isadigit{2}}{\isachardot}\ {\isasymAnd}n{\isachardot}\ {\isasymlbrakk}n\ {\isasymin}\ Even{\isachardot}even{\isacharsemicolon}\ n\ {\isacharminus}\ {\isadigit{2}}\ {\isasymin}\ Even{\isachardot}even{\isasymrbrakk}\isanewline +\isaindent{\ {\isadigit{2}}{\isachardot}\ {\isasymAnd}n{\isachardot}\ }{\isasymLongrightarrow}\ Suc\ {\isacharparenleft}Suc\ n{\isacharparenright}\ {\isacharminus}\ {\isadigit{2}}\ {\isasymin}\ Even{\isachardot}even% +\end{isabelle}% +\end{isamarkuptxt}% \isamarkuptrue% +\isacommand{apply}\ auto\isanewline \isamarkupfalse% -\isamarkupfalse% +\isacommand{done}\isamarkupfalse% % \begin{isamarkuptext}% ...and prove it in a separate step% @@ -101,11 +149,13 @@ \isamarkuptrue% \isacommand{lemma}\ Suc{\isacharunderscore}Suc{\isacharunderscore}even{\isacharunderscore}imp{\isacharunderscore}even{\isacharcolon}\ {\isachardoublequote}Suc\ {\isacharparenleft}Suc\ n{\isacharparenright}\ {\isasymin}\ even\ {\isasymLongrightarrow}\ n\ {\isasymin}\ even{\isachardoublequote}\isanewline \isamarkupfalse% +\isacommand{by}\ {\isacharparenleft}drule\ even{\isacharunderscore}imp{\isacharunderscore}even{\isacharunderscore}minus{\isacharunderscore}{\isadigit{2}}{\isacharcomma}\ simp{\isacharparenright}\isanewline \isanewline \isanewline \isamarkupfalse% \isacommand{lemma}\ {\isacharbrackleft}iff{\isacharbrackright}{\isacharcolon}\ {\isachardoublequote}{\isacharparenleft}{\isacharparenleft}Suc\ {\isacharparenleft}Suc\ n{\isacharparenright}{\isacharparenright}\ {\isasymin}\ even{\isacharparenright}\ {\isacharequal}\ {\isacharparenleft}n\ {\isasymin}\ even{\isacharparenright}{\isachardoublequote}\isanewline \isamarkupfalse% +\isacommand{by}\ {\isacharparenleft}blast\ dest{\isacharcolon}\ Suc{\isacharunderscore}Suc{\isacharunderscore}even{\isacharunderscore}imp{\isacharunderscore}even{\isacharparenright}\isanewline \isanewline \isamarkupfalse% \isacommand{end}\isanewline