Ken Dickey wrote:
> But computational infinities are not really numbers.

That's all a matter of definition. People used to think that
zero "is not really a number."  Some may think that a number
is anything that obeys certain mathematical laws.

I think of the type "extended-exact-rational" as comprising
fractions plus 1/0 and -1/0.  I think that extended set has some
nice properties, providing reasonable definitions for some
otherwise undefineds operation.  On the other hand, some
operations, such as (+ 1/0 -1/0), remain undefined.

Aesthetically, I like having 1/0 and -1/0  as exact numbers.
Not being a mathematician, I won't express a strong opinion, though.

> BTW, as markers I would expect
>  (eq? 1/0 1/0) -> #t

Likewise if they're viewed as exact numbers.
--
	--Per Bothner
xxxxxx@bothner.com   http://per.bothner.com/