[R6RS] NaNs and infinities

[dyb at cs.indiana.edu]

> From today's conference call, it sounds as though we are
> agreed to write the R6RS as though implementations have
> IEEE-like infinities and NaNs, allowing implementations
> to raise an &implementation-restriction exception when
> can't represent an infinite or NaN that the R6RS specifies
> as the result of some computation.

Correct.

> Applying that decision to my original message in this
> thread got rid of all of the totally unspecified values!

That's much nicer.

> Some examples still allow 0 or 0.0, or +inf.0 or an
> exception.

... or +nan.0 or an exception.

> (* +nan.0 x)  ==>  +nan.0

Only when x is not 0.  (* +nan.0 0) ==> 0 or +nan.0

> (max +inf.0 x)  ==>  +inf.0
> (min -inf.0 x)  ==>  -inf.0

Do these hold when x = +nan.0, or do you want
(max x +nan.0) = (min x +nan.0) = +nan.0?

Thanks for putting this all together.

Kent