Henning Thielemann <[email protected]> wrote: > >> A code doing addition and substraction of some sort. >> A property such as "X = (X add Y) sub Y" is easily falsifiable when >> the number of bits of your integer is too small for your numbers. > > Since fix-width words represent modulo-arithmetic, your law would even hold > in case of overflows.
True in this very example, but it's overly simplistic and I chose it just for the sake of illustration. A property such as "X = (X mul Y) div Y", with Y != 0 (of course ;-), Y prime wrt 2^nbBits (nbBits being the size of your integers), and the intermediate product exceeding 2^nbBits would fail miserably... --Serge _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
