From: utzoo!decvax!yale-com!leichter
Newsgroups: net.math
Title: Re: The Funny Nature of Infinity
Article-I.D.: yale-com.733
Posted: Wed Jan 26 21:26:05 1983
Received: Sun Jan 30 09:13:32 1983
References: ihuxe.193

In fact:

Def:  A is INFINITE if and only if there is a proper subset B of A such that
A and B can be put in one-to-one correspondence.

(If you are used to some other definition of "infinite" you may find it en-
lightening to prove the two definitios equivalent.)
							-- Jerry
						decvax!yale-comix!leichter