> Nice, that was helpful. I added some query methods to Numeric, eg.
> finite?, infinite?, ... and did this:
>
>   UNDEFINED = InfinityClass.instance(0)
>   INFINITY  = InfinityClass.instance(1)
>
>   NaN = UNDEFINED
>   Inf = INFINITY
>   PosInf = INFINITY
>   NegInf = -INFINITY

Great.  Note that (NaN == NaN) == False, but I think the rest of the
relations are straightforward.

Hadley