[Haskell-cafe] Re: Induction (help!)

Achim Schneider barsoap at web.de
Wed May 7 20:29:38 EDT 2008

PR Stanley <prstanley at ntlworld.com> wrote:

> Hi
> One of you chaps mentioned the Nat data type
> data Nat = Zero | Succ Nat
> Let's have
> add :: Nat -> Nat -> Nat
> add Zero n = n
> add (Succ m)n = Succ (add m n)
> Prove
> add m Zero = m
> I'm on the verge of giving up on this. :-(

The important point is to learn to regard an infinite number of
terms as one term, and how to mess with it without allowing individual
terms to escape or dangle around.

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