Nick Dokos writes: > Jussi Piitulainen wrote: > > They recognize modular arithmetic but for some reason insist that > > there is no such _binary operation_. But as I said, I don't > > understand their concern. (Except the related concern about some > > programming languages, not Python, where the remainder does not > > behave well with respect to division.) > > They are probably arguing that it's uniquely defined only on ZxN and > that there are different conventions to extend it to ZxZ (the > programming languages problem that you allude to above - although I > don't know what you mean by "does not behave well wrt division").
I think Boute [1] says Standard Pascal or some such language failed to have x div y + x rem y = x, but I can't check the reference now. That at least waes what I had in mind. Having x rem y but leaving it underspecified is another such problem: then it is unspecified whether the equation holds. [1] <http://en.wikipedia.org/wiki/Modulo_operation> > If you choose one convention and stick to it, it becomes a > well-defined binary operation. That's what I'd like to think. -- http://mail.python.org/mailman/listinfo/python-list