Raymond Smullyan died on February 6, 2017 at age 97, a brilliant mathematical logician, philosopher, magician, musician, and several other disciplines. I should provide a link or two or three or more, but if you are interested, just google him. There is a really huge amount there. One of his more amusing yet deep books bore the title, "What is the Name of this Book?"
It is many years since I have seen him, but I knew him personally, and he impressed the living daylights out of me, not merely for his intellect, but also his great and deep wit. He always had everyone around him laughing, and in a world that has always been full of horrors, there is a great virtue in that.
He was one of those who recognized that my late old man had proven the seriously clear and useful version of Godel's Incompleteness Theorem (actually two theorems), the version that makes it clear that consistency implies incompleteness, assuming one is dealing with a sufficiently rigorous logical system. Thus he argued they should be called the Godel-Rosser theorems, as they are called by many in Europe. The key to the "Rosser Trick" is the "Rosser Sentence" that "For every proof of this statement there is a shorter proof of its contradiction." Yeah, that really kills it. I mean, What is the Name of this Book anyway?
As a strictly personal and youthful remembrance, I can report that when I was about 8, give or take a year, he pulled a dime out of my ear that I did not know was there. But then, that is the sort of thing magicians do.
Barkley Rosser (Jr.)