Talk:Open Set Disjoint from Set is Disjoint from Closure

To check - $A$ doesn't actually have to be open here right? The chain of reasoning only needs $S \setminus B$ to be closed. Caliburn (talk) 17:41, 14 March 2023 (UTC)

I believe you are correct. This page was posted by someone who no longer contributes, so it is not possible to check with them where the result comes from.

It is worth tracking back through to the pages which link to this, to see whether there is any dependency there to force $A$ to be open -- but even if there is, the result you suggest is stronger than this one. Hence I would have no immediate beef with the condition on $A$ being relaxed. Exactly how one would word the title is not a trivial problem, of course. --prime mover (talk) 18:25, 14 March 2023 (UTC)

Name actually turned out better than before. Caliburn (talk) 21:59, 14 March 2023 (UTC)

Would you amend the links while you're up here? If not I'll do it tomorrow. --prime mover (talk) 23:20, 14 March 2023 (UTC)