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Re: My ideas about infinity in Scheme (revised)

This page is part of the web mail archives of SRFI 70 from before July 7th, 2015. The new archives for SRFI 70 contain all messages, not just those from before July 7th, 2015.

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
per@xxxxxxxxxxx   http://per.bothner.com/