[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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.

*To*: srfi-70@xxxxxxxxxxxxxxxxx*Subject*: Re: My ideas about infinity in Scheme (revised)*From*: Ken Dickey <Ken.Dickey@xxxxxxxxxxxxxx>*Date*: Fri, 20 May 2005 18:21:47 -0700*Delivered-to*: srfi-70@xxxxxxxxxxxxxxxxx*In-reply-to*: <20050520022827.D9E0C134@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>*Organization*: BitWize Consulting*References*: <20050520022827.D9E0C134@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>*User-agent*: KMail/1.7

On Thursday 19 May 2005 19:28, Chongkai Zhu wrote: > 1. We need both exact (rational) infinity and inexact infinity, that is, > four special numbers: > > 1/0 -1/0 +inf.0 -inf.0 > > The first two are rational and thus exact. But computational infinities are not really numbers. They are special markers for places where limits of the number system are exceeded. Being outside the system, they can't be exact. It is like talking about the duration of events outside of space/time. There is no symmetry. We speak of 1/0, 0/0, -1/0 as numbers in the same way we speak of '() as the end of a list or #!eof as the end of a file. They are singleton limit markers with no value but for computational tests. BTW, as markers I would expect (eq? 1/0 1/0) -> #t Cheers, -KenD

**Follow-Ups**:**Re: My ideas about infinity in Scheme (revised)***From:*Per Bothner

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

- Prev by Date:
**Re: FP Hardware** - Next by Date:
**Re: My ideas about infinity in Scheme (revised)** - Previous by thread:
**My ideas about infinity in Scheme (revised)** - Next by thread:
**Re: My ideas about infinity in Scheme (revised)** - Index(es):