OK, "just pairs" have no arithmetic, but one way of defining arithmetic is to treat the pairs as complex numbers. Or as mantissa and exponent. Or as something else. So there's nothing wrong, IMO, to make pairs an instance of Num if you so desire. (Though I'd probably introduce a new type.)
On Mon, Oct 5, 2009 at 6:46 PM, Miguel Mitrofanov <miguelim...@yandex.ru> wrote: >> "Just pairs" have no natural arithmetic upon them. > > Exactly my point. > >> BTW. the missing term of M.M. is DUAL NUMBERS. > > Remembered this already. Thanks anyway. > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe