number printing problems in 5.9.3.99rc2 xmaxima on windows/GCL

On 8/28/06, Robert Dodier <robert.dodier at gmail.com> wrote:
> On 8/28/06, Richard Fateman <fateman at cs.berkeley.edu> wrote:
>
> > I think it would lead to confusion if there were two objects that were
> > different but printed the same.  So a floating point infinity should
> > look different from the atom $inf.  Or alternatively, we could make them
> > REALLY the same, not just on output.  The treatment of inf and floating
> > inf are inconsistent at the moment.
>
> Well, for now let's just output inf_float, minf_float, nan_float or
> something like that.
> Or float_inf, float_minf, float_nan, same thing.
> Or write fp in place of float if "float" seems too strongly suggestive
> of single precision.

I agree.

> Eventually I'd like to see a unification of the symbolic and numerical stuff.

Well, the semantics aren't the same today, and I don't see how we
could make them the same.  If the output of a strictly floating-point
calculation (some numeric library) is float_inf, there is no way of
knowing whether it is 10^400 or true positive infinity.

For similar reasons, 0 and 0.0 should not be considered to be the same
thing (though we are currently sloppy about this).

The semantics of float_nan are perhaps close enough to UND to make
them the same.

Most importantly, let's make sure that und-und, inf-inf, inf/inf, etc.
don't simplify incorrectly....

          -s