Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!alice!dutoit!dmr From: dmr@dutoit.UUCP Newsgroups: net.math Subject: Re: How Many Continuous Functions Are There Message-ID: <2063@dutoit.UUCP> Date: Sat, 12-Oct-85 00:22:43 EDT Article-I.D.: dutoit.2063 Posted: Sat Oct 12 00:22:43 1985 Date-Received: Mon, 14-Oct-85 03:23:29 EDT Lines: 22 There seems to be a general belief in recent messages here that aleph-1 (second infinite cardinal) equals C (power of the continuum). C is defined as the cardinality of the real numbers, and by simple Cantorian arguments is equal to the cardinality of the subsets of integers, which is what is meant by 2^aleph-0. But the other belief is called the Continuum hypothesis, and Paul Cohen showed about 20 years ago that it is independent of the usual axioms of set theory (can't be proved; may consistently be asserted or denied). You are free to assume that C is much bigger than practically any aleph you can name (well, not aleph-C). In particular, the following fragment is lunacy: >There are C polynomials ---> there are aleph-0 * C countable subsets. > >Incidentally, C = aleph-1. >( C <= the number of finite subsets of reals = aleph-1 >and C >= the number of reals = aleph-1 --> C = aleph-1) >and so aleph-0 * C = aleph-2. Dennis Ritchie