> | 
> | So, what *is* -5 MOD 3?
> | 
> 
> -2

I hope not.  If you are really serious about using modular arithmetic
then you probably want to use something like PARI GP where -5 mod 3
is -5 mod 3, belonging to the data type of integers mod 3.  -2 mod 3
and 1 mod 3 are alternate representations of the same value.  If you
aren't serious about modular arithmetic and want the result to be an
integer then I think you are shooting yourself in the foot if you
implement it as anything other than -5 mod 3 == 1.  I want to be able
to test whether n is odd with `if ( n % 2 == 1 ) ...'  Of course, I'm
a mathematician rather than a CS person, but I think the other
convention has nothing to recommend it.
--
John Stalker
University of Dublin, Trinity College
School of Mathematics

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