author | nipkow |
Wed, 19 Apr 2000 12:59:38 +0200 | |
changeset 8749 | 2665170f104a |
child 9145 | 9f7b8de5bfaf |
permissions | -rw-r--r-- |
\begin{isabelle}% % \begin{isamarkuptext}% \noindent Define the datatype of binary trees% \end{isamarkuptext}% \isacommand{datatype}~'a~tree~=~Tip~|~Node~{"}'a~tree{"}~'a~{"}'a~tree{"}% \begin{isamarkuptext}% \noindent and a function \isa{mirror} that mirrors a binary tree by swapping subtrees (recursively). Prove% \end{isamarkuptext}% \isacommand{lemma}~mirror\_mirror:~{"}mirror(mirror~t)~=~t{"}\end{isabelle}%