0 <= (x MOD y) < y or y < (x MOD y) <= 0
-- `Programming in Oberon,' M. Reiser and N. Wirth, Page 36.
(which is available as a pdf from the web)
> On Thu, Dec 15, 2005 at 10:53:06PM -0600, erik quanstrom wrote:
>> | Please note that this definition of DIV and MOD differs from the
>> | definition given in [M. Reiser, N. Wirth. Programming in Oberon. p.
>> | 36]:
>> | x = (x DIV y) * y + (x MOD y), and
>> | 0 <= (x MOD y) < y
> ^^^^^^^^^^^^^^^^^^
>> |
>> | So, what *is* -5 MOD 3?
>> |
>>
>> -2
>
> Are you sure? It looks to me more than it'd be +1. Wirth's definition
> above would tend to indicate that x MOD y is always positive, unless I'm
> reading it wrong, or that's not the whole story (and I confess I'm too
> lazy to look up the definitions in context). If I'm right, that would
> also imply that x DIV y tends more wards negative infinity than zero
> for negative numerators.
>
> - Dan C.
