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From: Dusko Pavlovic <dusko@kestrel.edu>
To: CATEGORIES LIST <categories@mta.ca>
Subject: Re:  Cauchy completeness of Cauchy reals
Date: Fri, 24 Jan 2003 18:21:00 -0800	[thread overview]
Message-ID: <3E31F48C.90308@kestrel.edu> (raw)
In-Reply-To: <15920.65167.864071.575967@acws-0054.cs.bham.ac.uk>

>
>
>Set. Do you think your construction works in any topos?
>
the coalgebraic structures are defined using just arithmetic. in the
first one, there is the "no infinite sequences of 1s" condition, which i
am reminded depends on markov's principle; but that is just used in the
explanation. i don't think there are other constraints.

>If so, what
>would "Cauchy reals" mean precisely in this general context?
>
it means fundamental sequence, with the equivalence relation in the
"lazy" mode, a la bishop, as described in andrej bauer's message.

if my last night's posting makes sense, then these constructivist cauchy
reals make a whole lot of difference, because they really let you avoid
the choice and get limits.

-- dusko







  reply	other threads:[~2003-01-25  2:21 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-01-15 14:00 Generalization of Browder's F.P. Theorem? Peter McBurney
2003-01-16 14:04 ` Steven J Vickers
2003-01-16 23:00   ` Prof. Peter Johnstone
2003-01-16 23:05   ` Michael Barr
2003-01-21 18:11     ` Andrej Bauer
2003-01-22 10:13       ` Cauchy completeness of Cauchy reals Martin Escardo
2003-01-22 23:33         ` Dusko Pavlovic
2003-01-23 19:56           ` Category Theory in Biology Peter McBurney
2003-01-24  8:51           ` Cauchy completeness of Cauchy reals Martin Escardo
2003-01-25  2:21             ` Dusko Pavlovic [this message]
2003-01-25 16:24               ` Prof. Peter Johnstone
2003-01-27  3:57                 ` Alex Simpson
2003-01-23  6:29         ` Vaughan Pratt
2003-02-04  0:47           ` Vaughan Pratt
2003-02-05 16:06             ` Prof. Peter Johnstone
2003-01-23  9:50         ` Mamuka Jibladze
2003-01-24  1:34         ` Ross Street
2003-01-24 16:56       ` Dusko Pavlovic
2003-01-24 19:48         ` Dusko Pavlovic
2003-01-27 17:41 Andrej Bauer
2003-01-28  1:50 ` Alex Simpson
2003-01-28  9:44 Andrej Bauer
2003-01-28 20:51 Dusko Pavlovic
2003-01-29  2:00 ` Toby Bartels
2003-01-29  8:35 ` Alex Simpson
2003-02-04  9:15   ` Dusko Pavlovic
2003-02-05 20:56     ` Toby Bartels

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