User talk:Leigh.Samphier

From ProofWiki
Jump to navigation Jump to search

Welcome to ProofWiki! Since you're new, you may want to check out the general help page. It's the best first stop to see how things are done (next to reading proofs, of course!). Please feel free to contribute to whichever area of mathematics interests you, either by adding new proofs, or fixing up existing ones. If you have any questions please feel free to contact one of the administrators, or post your question on the questions page.

Here are some useful pages to help get you started:

  • Community Portal - To see what needs to be done, and keep up to date with the community.
  • Recent Changes - To keep up with what's new, and what's being added.
  • Check out our house style if you are keen on contributing.
  • Main Page talk - This is where most of the main discussions regarding the direction of the site take place. If you have any ideas, please share them!

Cheers! prime mover (talk) 16:16, 10 October 2016 (EDT)

"Sources" section

Please, if you think the source links are going to be compromised by refactoring you have done, please do *not* just delete the links. Please add an invocation of {{SourceReview}} at the top of the Sources section so that anyone who has a copy of that work can go through and fix the links.

Many thanks. --prime mover (talk) 11:35, 1 July 2019 (EDT):

I’ll be sure to do this in the future. Although, in this case, the links I removed were links that I inadvertently introduced through a copy/paste operation. So, I thought I was correcting a mistake. The original flow through the source is undisturbed. Of course that doesn’t negate the the need for the {{SourceReview}}. —Leigh.Samphier (talk) 17:28, 1 July 2019 (EDT)
Without actually checking (I have the book somewhere, not immediately sure where), the actual situation is probably that a subset of the definitions given are in S&S and the statement of their equivalence is mentioned, but not proved. So a true reflection of the contents of the book will be fiddly to establish, and will be a job for a long weekend (of which I do not have many for a while). --prime mover (talk) 17:39, 1 July 2019 (EDT)

Please, I ask again: please add an invocation of {{SourceReview}} at the bottom of pages which you refactor. I just happen to be progressing through Steen and Seebach again to correct citation links, and I noticed that work needs doing to correct the prev-next links in Definition:Boundary (Topology). I'm going to need to fix them, which itself is no big deal, but if I had not noticed this, they would not have been done, and integrity would have been compromised. --prime mover (talk) 07:50, 17 May 2020 (EDT)

Glad you caught it. My apologies. --Leigh.Samphier (talk) 08:04, 17 May 2020 (EDT)

Adding mathematicians

A quick heads-up: as and when you add new mathematicians to $\mathsf{Pr} \infty \mathsf{fWiki}$, you may also want to add them to the appropriate pages in the Mathematician:Mathematicians page: one link into the overall chronological list of mathematicians (according to which century (approximately) they were born) and one into the "nation" list (according to exactly where they were born and/or naturalised, again in chronological order of birth date). The latter can get complicated if they were born in a place which has had a lot of political upheaval -- Germany in particular is fiddly because of all the different nation-states pre 1870-ish.

Cheers --prime mover (talk) 08:55, 10 September 2019 (EDT)

overdue proofread exercise

I have been through and performed a proofreading exercise on a large number of your pages, as you have noticed. There are probably some I've missed, but I think it's the main bulk of what you put up in the last 2 years or so.

I will do this again the next time I have a long weekend which I don't know what to do with.

Let me know if there is anything you find I've missed, and/or have questions on what I have done. --prime mover (talk) 09:44, 30 August 2020 (UTC)

Question about Closure in Subspace and Closure of Subset in Subspace

To my eye, these results are exactly the same.

Can you cast your eye over them quickly to see if that is correct?

I intend that they be merged. The proof in Closure of Subset in Subspace is far more neat than (yet appears to say exactly the same thing as) the proof in Closure in Subspace, so I would recommend we keep the former and throw away the latter.

I may have missed something really subtle here, which is why the second opinion.

Note that the corollary has already been moved. --prime mover (talk) 07:39, 12 January 2021 (UTC)

The only difference in the theorem statement is that Closure of Subset in Subspace includes $H = \O$ which is not included in Closure in Subspace. The proofs are along the same lines. The proof in Closure of Subset in Subspace is more succinct, and the proof in Closure in Subspace is more explanatory for the novice. But I agree with your recommendation. --Leigh.Samphier (talk) 09:29, 12 January 2021 (UTC)
A quick glance confirms that $H = \O$ does not affect the result. If $H = \O$ then $A = \O$ and $\map \cl A = \O$ and so on, and everybody goes home happy.
At one time we were being careful to exclude the topological space where $S = \O$ but it was pointed out that this is an unnecessary complication, and that null spaces should indeed properly be considered as valid topological spaces.
If you have the headspace, feel free to take a glance at Closure of Subset in Subspace/Corollary 2 and see if you can complete the proof -- I seem to be unable to make headway with it. My ability to figure things out is deteriorating. --prime mover (talk) 10:45, 12 January 2021 (UTC)
Proof for Closure of Subset in Subspace/Corollary 2 has been added. --Leigh.Samphier (talk) 05:38, 13 January 2021 (UTC)