From: "Fred E.J. Linton" <fejlinton@usa.net>
To: Florian Lengyel <florian.lengyel@gmail.com>,
FEJ Linton <FLinton@wesleyan.edu>
Cc: <categories@mta.ca>
Subject: Re: The Idea of Structure as Data and Conditions
Date: Mon, 28 May 2012 23:15:34 -0400 [thread overview]
Message-ID: <043qeCDoI7392S02.1338261334@web02.cms.usa.net> (raw)
On Mon, 28 May 2012 07:25:19 PM EDT, Florian Lengyel
<florian.lengyel@gmail.com>, protesting my assertion that
>> Virtually no one ever wants to restrict attention to functions that
respect
>> (preserve or reflect) membership (other than "preserve" between ordinals).
remonstrated that
> Within set theories that satisfy the axiom of regularity, one's attention
> is restricted to functions that both preserve and reflect self-membership.
>
> f(x) \in f(x) iff x\in x
Hereto, I in turn ask: Why only self-membership? why not membership outright
-- f(x) \in f(y) if (and/or only if) x \in y -- ?
And how often, really, do we actually impose either of those restrictions? (Or
did FL inadvertently omit a "sometimes" between "is" and "restricted" :-) ?)
Cheers, -- Fred
[For admin and other information see: http://www.mta.ca/~cat-dist/ ]
next reply other threads:[~2012-05-29 3:15 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-29 3:15 Fred E.J. Linton [this message]
2012-05-29 13:28 ` Colin McLarty
-- strict thread matches above, loose matches on Subject: below --
2012-05-25 22:09 Ellis D. Cooper
2012-05-26 23:48 ` Michael Barr
2012-05-27 18:16 ` Eduardo J. Dubuc
2012-05-28 6:00 ` FEJ Linton
2012-05-29 13:28 ` Staffan Angere
2012-05-30 6:26 ` Vaughan Pratt
2012-05-27 13:02 ` Charles Wells
[not found] ` <CABZOOqZ54NtG1n3K4f8o6mMRSgZ_2yVjE6S+-UWkQSO_PXi1tQ@mail.gmail.com>
2012-05-27 13:06 ` Charles Wells
2012-05-27 23:25 ` Vaughan Pratt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=043qeCDoI7392S02.1338261334@web02.cms.usa.net \
--to=fejlinton@usa.net \
--cc=FLinton@wesleyan.edu \
--cc=categories@mta.ca \
--cc=florian.lengyel@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).