Thanks for your reply. The Halmos book is on my to-read list for some months. Will bump it! I also started reading the Cheng book, but I did not finish it eit

Thanks for your reply. The Halmos book is on my to-read list for some months. Will bump it! I also started reading the Cheng book, but I did not finish it either. Let me know the name of the Diff. Geometry book when you remember it. And wish you the best on your plans of circling back.