[Haskell-cafe] some simple proof exercises

[Michaeljohn Clement]

> http://www.thenewsh.com/%7Enewsham/formal/problems/set1.html

In P2 there is a typo:

 8:      Assume: xs ++ [] = zs                indhypothesis
                 ^^

I know very little Haskell but the proofs were nonetheless easy enough
to follow.

HTH,
Michaeljohn