Isn't a space with the cofinite topology quasicompact but not compact since it is not Hausdorff? — Preceding unsigned comment added by 73.50.103.143 (talk)...

topology be merged into Cofinite topology. I think that the content in the Cocountable topology article is duplicated in the Cofinite topology article. Dsou...

in the ultraproduct. Proper subsets of the ultrafilter, including the cofinite filter on I, would also imply the truth of the theorem as applied to models...

because ultrafilters are defined more generally on posets and Fréchet/cofinite filters more specifically for a power set lattice. Perhaps there is a representation...

thought that a canonical example of a free ultrafilter was the set of all cofinite subsets of the natural numbers. I found it curious that it's not included...

Rsmoore (talk) 07:38, 28 August 2008 (UTC) D being cofinite does not make landing in D certain. Also, cofinite sets only have the smallest cardinality on non-null...

{ 0 , 1 } ω / ≈ {\displaystyle E=\{0,1\}^{\omega }/\approx } with this cofinite string idea. That's fine, too. Intuitively, it is saying that x ≈ y {\displaystyle...

T_{1}} counterexample consider N {\displaystyle \mathbb {N} } with the cofinite topology. Jean Abou Samra (talk) 00:08, 3 December 2025 (UTC) Right --...

(UTC) So now we have: "Ia-finite. Each subset of S is either finite or cofinite or both.", whereas before there was: "Ia-finite. S is not equal to the...

in the example of the power set of a set, and of the set of finite and cofinite subsets, that "for these rings, the additive identity 0 is ∅, and the multiplicative...

almost all palindromic numbers are composite". Either there is only a cofinite set of palindrome primes (i.e. allmost all palindrome numbers are composite)...

topology and box topology: both direct sums and product topologies have a cofiniteness condition that direct products and box topologies don't have. GeoffreyT2000...

basic infinite examples (before one gets to extra structure) like finite-cofinite or intervals, which one can even find in Springer EOM or in Givant and...

subsets that are finite or cofinite forms a Boolean algebra. That is, all of the finite subsets together with all of the cofinite subsets. So complementation...

around: R with the lower limit topology isn't path-connected, but R with the cofinite topology is. The fact that path-connected spaces are connected follows...

principal filters like those. An example of a non-principal filter is the cofinite filter on an infinite set. Caveat: I'm really only talking about Filter...

21 January 2010 (UTC) Not really, as far as I can see. QN modulo the cofinite filter is a rather unpleasant object (it has uncountably many square roots...

first-order statements between H and R, and that this model, with the cofinite filter common to all nontrivial ultrafilters, does not require the axiom...

21:54, 31 August 2005 (UTC) Sure. An example is the set of all finite and cofinite subsets of the natural numbers (with the obvious interpretations of the...

The top two candidates for that, both countable, would be finite and cofinite sets, which is atomic, and the Boolean operations, aka the free Boolean...