On Fri, 2007-12-14 at 00:03 -0700, Robert Dodier wrote:
> At this point I think I;'m in favor of "set builder"
> notation like { x | x < 5 and x > -2 } (or with "s.t." instead of "|"
> or whatever). That covers the special cases (open vs closed vs
> half-open) and generalizations (complement, union, Cartesian product
> of intervals, spheres, arbitrary predicates) without needing any
> additional notations.
Does that proposal also include defining intervals such as:
{ x | (x < 5 and x > -2) or (x < 9 and x > 8) }
{ y | y < -5 and y > 5 }
and doing arithmetic with them?
Regards,
Jaime