author | nipkow |
Wed, 19 Apr 2000 12:59:38 +0200 | |
changeset 8749 | 2665170f104a |
parent 8745 | 13b32661dde4 |
child 8771 | 026f37a86ea7 |
permissions | -rw-r--r-- |
(*<*) theory "cases" = Main:; (*>*) lemma "(case xs of [] \\<Rightarrow> [] | y#ys \\<Rightarrow> xs) = xs"; apply(case_tac xs); txt{* \begin{isabellepar}% ~1.~xs~=~[]~{\isasymLongrightarrow}~(case~xs~of~[]~{\isasymRightarrow}~[]~|~y~\#~ys~{\isasymRightarrow}~xs)~=~xs\isanewline ~2.~{\isasymAnd}a~list.~xs=a\#list~{\isasymLongrightarrow}~(case~xs~of~[]~{\isasymRightarrow}~[]~|~y\#ys~{\isasymRightarrow}~xs)~=~xs% \end{isabellepar}% *} apply(auto).; (**) (*<*) end (*>*)