User talk:106.195.70.57

August 2021
Hello, I'm Rdp060707. I noticed that you made a change to an article, Positively invariant set, but you didn't provide a source. I’ve removed it for now, but if you’d like to include a citation to a reliable source and re-add it, please do so! If you think I made a mistake, or if you have any questions, you can leave me a message on my talk page. Thanks. Rdp060707&#124;talk 06:57, 18 August 2021 (UTC)