Virgil
Posts:
9,012
Registered:
1/6/11


Re: Countably Infinite Sets
Posted:
Dec 28, 2012 12:41 AM


In article <22a702acb0b44c5eb4f37d094499f431@r13g2000vbd.googlegroups.com>, netzweltler <reinhard_fischer@arcor.de> wrote:
> Does the set {{1}, {1,2}, {1,2,3}, ...} contain all natural numbers?
Uunless one's naturals are sets of numerals rather than numerals, or sets of sets, as is more usual, it does not contain any of them.
But it bijects nicely with anyone's set of natural numbers 

