A great and wonderful logician and philosophy professor has died.  Raymond Smullyan who wrote widely on logic and mathematics.  I used his logic books  in my courses...Here is his obit from the NYTimes...check it out..   Wonderful Puzzle books such as "What is the Name of this Book?"

https://www.nytimes.com/2017/02/11/us/raymond-smullyan-dead-puzzle-creator.html?rref=collection%2Fsectioncollection%2Fobituaries&action=click&contentCollection=obituaries&region=rank&module=package&version=highlights&contentPlacement=5&pgtype=sectionfront