The World's Hardest Logic Puzzle Ever!
Complete this exercise, which will give you an opportunity to solve a difficult logic puzzle. Watch the video on this puzzle for a discussion of the solution.
This is not really a tutorial, but an exceedingly hard logic puzzle for you to solve. According to the late philosopher and logician George Boolos, who was a great teacher and logician at MIT, the hardest (recreational) logical puzzle is one that was invented by the logician and puzzle-master Raymond Smullyan, and modified slightly by the computer scientist John McCarthy.
Here is the puzzle:
SOLUTION
Here is the TED-Ed video on this puzzle, with a discussion of the solution:
Source: Joe Lau and Jonathan Chan, https://philosophy.hku.hk/think/logic/hardest.php This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License.