Trivial, they're in the same category with add and multiply. Check out http://lambda-the-ultimate.org/node/587 http://lambda-the-ultimate.org/node/587 for some

Trivial, they're in the same category with add and multiply. Check out http://lambda-the-ultimate.org/node/587 http://lambda-the-ultimate.org/node/587 for some non trivial examples.