In math, we get to make up anything we want, and then reason from it. If you don't believe me, you just haven't studied enough higher math. What is important is whether it is consistent and useful.

Well, I did study higher maths. And your argumentation is basically right. For example, if you ask how much is 2+2? one should reply it depends. Why? Because you ain't saying anything about the base on which respect you are calculating the result (e.g., 2+2=0 in the weird 4-based Z(4) numerical system -the integers modulo 4).

But we ain't talking about higher mathematics here, that's plain algebra in the old 10-based numerical system Z, the dear old integer mathematics we studied in the early years of the school, where my teacher used to hit me on my face if I wrote a negative reminder (or one that was too big). And in dear old mathematics the modulus is always positive.

Ciao!
--bronto

Update: thanks to Enlil for pointing errors around; fixed (hopefully :-)

The very nature of Perl to be like natural language--inconsistant and full of dwim and special cases--makes it impossible to know it all without simply memorizing the documentation (which is not complete or totally correct anyway).
--John M. Dlugosz