From: Mr R. Forster
Subject: HELP NEEDED !
Date: Fri, 10 Mar 1995 13:25:34 +0000
Message-ID: <D587yM.Mrn@liverpool.ac.uk>

I am having trouble answering the question, detailed below,
can anybody help ?

Write a recursive function called r-replace which given 3 arguments,
the first two of which are atoms and the third of which is a list,
which replaces all occurences of the 1st argument with the 2nd in
the 3rd. e.g.

>(r-replace 1 2`(1 2 3 4 1 3 4))
(2 2 3 4 2 3 4)