Date: Mar 29, 2013 6:24 PM
Author: Shmuel (Seymour J.) Metz
Subject: Re: Using classes instead of sets

In <>, on 03/29/2013
at 06:07 AM, quasi <quasi@null.set> said:

>There are certain concepts for which sets are inadequate and classes
>come to the rescue. For example, we need the class concept if we
>want to define an equivalence on the collection of all groups, since
>that collection is not a set.

There's no such set in ZFC, but there are set theories in which it
exists aqnd is a set.

Shmuel (Seymour J.) Metz, SysProg and JOAT <>

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