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)