Logic puzzle

This branch was pioneered by Charles Lutwidge Dodgson, who is better known under his pseudonym Lewis Carroll, the author of Alice's Adventures in Wonderland. In his book The Game of Symbolic Logic he introduced a game to solve problems such as

1. some games are fun
2. every puzzle is a game

Are all puzzles fun?

Of course, this example is trivial. Dodgson goes on to construct much more complex puzzles consisting of up to 8 thesis.

In the second half of the 20th century mathematician Raymond M. Smullyan has continued and expanded the branch of logic puzzles with books as "the Lady and the Tiger", "To mock a mocking bird" and "Alice in puzzle-land".