Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
Drexel University or The Math Forum.


Virgil
Posts:
8,833
Registered:
1/6/11


Re: Uncountable?
Posted:
Apr 25, 2014 3:12 AM


In article <Pine.NEB.4.64.1404250003140.11979@panix2.panix.com>, William Elliot <marsh@panix.com> wrote:
> Let C be a collection of open subsets of R that cover Q. > Can S = R  \/C ever be uncountable?
It cannot even be nonempty!
Every open cover of Q as a subset of R covers R. 



