[R6RS] IEEE 754 wizard help needed

[dyb at cs.indiana.edu]

> I should have been more clear: Assume the underlying representation
> *is* IEEE 754.  According to that, (sqrt -0.0) => -0.0, I believe, so
> that doesn't help.

If the underlying representation is IEEE 754, I think we should require
(/ 1.0 0.0) to evaluate to +inf.0.  Either way, (sqrt -0.0) might produce
an inexact zero imaginary component.

Kent