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*To*: Ken Dickey <Ken.Dickey@xxxxxxxxxxxxxx>*Subject*: Re: My ideas about infinity in Scheme (revised)*From*: Per Bothner <per@xxxxxxxxxxx>*Date*: Fri, 20 May 2005 19:52:18 -0700*Cc*: srfi-70@xxxxxxxxxxxxxxxxx*Delivered-to*: srfi-70@xxxxxxxxxxxxxxxxx*In-reply-to*: <200505201821.48150.Ken.Dickey@xxxxxxxxxxxxxx>*References*: <20050520022827.D9E0C134@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> <200505201821.48150.Ken.Dickey@xxxxxxxxxxxxxx>*User-agent*: Mozilla Thunderbird 1.0.2-1.3.2 (X11/20050324)

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/

**References**:**My ideas about infinity in Scheme (revised)***From:*Chongkai Zhu

**Re: My ideas about infinity in Scheme (revised)***From:*Ken Dickey

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