Mad with nice drawings

You really should visit the blog Math With Bad Drawings.

Credit: Ben Orlin

On February 10th, the world lost Raymond Smullyan: logician, puzzlemaster, and blue-ribbon Gandalf lookalike.

Even if you don’t know his name, you’ve probably wrestled with his logic puzzles. They share a whimsical sense of rigor: “You come to an island where there are two types of people: knights, who always tell the truth, and knaves, who always lie…” … (Math with Bad Drawings)