Hi,
I think in practice this wouldn't really be an issue. When you're using natural numbers, you tend to be in a situation where you're either numbering things statically, and not doing any calculations with them, or you're using them as a monoid, whereby things only increase.
take? primes? fibs? ackermanns? There are lots of things things were computation is performed on natural numbers, in fact, I'd say its relatively rare to find negative integers! See "What About the Natural Numbers" - "Colin Runciman" - it's a good read :) Thanks Neil _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe