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Topic:
Zero set
Replies:
7
Last Post:
May 31, 2012 3:12 AM




Re: Zero set
Posted:
May 30, 2012 5:57 AM


On Wed, 30 May 2012 01:38:35 0700, William Elliot <marsh@panix.com> wrote in <news:Pine.NEB.4.64.1205300128060.28313@panix2.panix.com> in sci.math,alt.algebra.help:
> On Wed, 30 May 2012, Butch Malahide wrote:
>> On May 30, 2:18 am, William Elliot <ma...@panix.com> wrote:
>>> If A is a zero subset of S, is cl S\A a zero subset?
>> Let S be a totally ordered set of order type omega_1 + 1 >> + omega^* with the order topology, and let A be the >> subset consisting of the first omega_1 + 1 elements of >> S. It seems to me that A is a zero set, but cl S\A is >> not a zero set.
> What's omega^*? The reverse of omega_1?
No: it's the reverse of omega.
[...]



