Talk:Topology/Bases

I have added a new problem, but it is not looking good as I don't know how to adjust the paragraph etc. settings. Could anyone put it right?

SPat (talk) 06:02, 30 March 2008 (UTC)

Problem sorted

SPat (talk) 02:19, 31 March 2008 (UTC)

Conditions for Being a Base
I have deleted the proof from this section. To be proven is an equivalence, but only an implication in one direction is shown. Also, the fact that $$\mathcal{B}\not\subseteq U$$ (since $$U\in \mathcal{T}\supseteq\mathcal{B}$$) clearly falsifies the proof.

This might be a minor error, but somebody definitely needs to go over it and check. It's removed for now.

Proof:

Let $$U$$ be any open set. Consider any element $$x\in U$$. There is an open set within $$\mathcal{B}\subseteq U$$. The union of all of them is $$U$$. Thus, any open set can be formed as a union of sets within $$\mathcal{B}$$.

--Jerome Baum (talk) 18:43, 24 November 2009 (UTC)


 * EDIT: Substitute "clearly falsifies the proof" with "presents a formal error" -- it's probably just a typo but I don't have the head to correct it right now. --Jerome Baum (talk) 18:46, 24 November 2009 (UTC)


 * ✅ JoergenB (discuss • contribs) 17:33, 13 August 2015 (UTC)