author | berghofe |
Mon, 16 Dec 2002 13:43:11 +0100 | |
changeset 13755 | a9bb54a3cfb7 |
parent 13739 | f5d0a66c8124 |
permissions | -rw-r--r-- |
(*<*) theory Snoc = Main: (*>*) subsection {* Lists *} text {* Define a primitive recursive function @{text snoc} that appends an element at the \emph{right} end of a list. Do not use @{text"@"} itself. *} consts snoc :: "'a list => 'a => 'a list" text {* Prove the following theorem: *} theorem rev_cons: "rev (x # xs) = snoc (rev xs) x" (*<*)oops(*>*) text {* Hint: you need to prove a suitable lemma first. *} (*<*) end (*>*)