home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: sci.logic
- Path: sparky!uunet!pmafire!mica.inel.gov!guinness!garnet.idbsu.edu!holmes
- From: holmes@garnet.idbsu.edu (Randall Holmes)
- Subject: Re: Impredicativity - was: Russell's Paradox
- Message-ID: <1992Nov6.191800.17025@guinness.idbsu.edu>
- Sender: usenet@guinness.idbsu.edu (Usenet News mail)
- Nntp-Posting-Host: garnet
- Organization: Boise State University
- References: <1992Nov4.073717.22625@CSD-NewsHost.Stanford.EDU> <1992Nov5.164251.29649@guinness.idbsu.edu> <1992Nov5.174527.22908@CSD-NewsHost.Stanford.EDU>
- Date: Fri, 6 Nov 1992 19:18:00 GMT
- Lines: 21
-
- In article <1992Nov5.174527.22908@CSD-NewsHost.Stanford.EDU> pratt@Sunburn.Stanford.EDU (Vaughan R. Pratt) writes:
- >In article <1992Nov5.164251.29649@guinness.idbsu.edu> holmes@garnet.idbsu.edu (Randall Holmes) writes:
- >>You do not "weaken" FA to AFA; ZFC- + FA and ZFC- + AFA are both
- >>stronger than ZFC-, but neither is stronger than the other.
- >
- >I guess this must be another of my misconceptions. My general
- >impresssion was that AFA was automatically true under FA, by virtue of
- >the latter saying that only "unwound" graphs were permitted, and that
- >every chain on the unwinding had to terminate. So what's an example FA
- >situation contradicting AFA?
- >--
- >Vaughan Pratt There's no truth in logic, son.
-
- AFA asserts the existence of a set (only one) which is its own sole
- element; FA asserts the impossibility of such a set.
-
- --
- The opinions expressed | --Sincerely,
- above are not the "official" | M. Randall Holmes
- opinions of any person | Math. Dept., Boise State Univ.
- or institution. | holmes@opal.idbsu.edu
-