On Tue, Oct 27, 2009 at 03:25:02PM +0000, Sam Mason wrote:
> If the absolute value of an interval was defined to strip out all the
> negation signs you'd get the "wrong" answers out.
Oops, forgot another reason! For maths to work (n) and (-(-n)) should
evaluate to the same value. Inverting all the signs, as negation does,
will ensure that these semantics remain.
--
Sam http://samason.me.uk/