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Is exact 0 "stronger" than inexact 0.0?



   (* 0 +inf.0)                           ==>  +nan.0
...
   (/ 0 0.0)                              ==>  unspecified
   (/ 0.0 0)                              ==>  +nan.0
   (/ 0.0 0.0)                            ==>  +nan.0

Why is only (/ 0 0.0) out of this set unspecified?

How should (/ 0 0) behave?

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The description of `+' and `*' says:

    If any of these procedures are applied to mixed non-rational real
    and non-real complex arguments, they either report a violation of
    an implementation restriction or return an unspecified number.

The only non-rational real numbers in current implementations are
+inf.0 and -inf.0.  Is this what was intended?

If so, calling them infinities would be less cryptic.

Shouldn't that sentence also appear in the description of `-' and `/'?

It allows return of "an unspecified number."  Does that allow a NaN to
be returned?