Some logic puzzles based on a theme in "What is the Name of this Book?" by Raymond Smullyan.

When Alice entered the Forest of Forgetfulness, she did not forget everything, only certain things. She often forgot her name, and the one thing she was most likely to forget was the day of the week. Now, the Lion and the Unicorn were frequent visitors to the forest. These two are strange creatures....

The Lion lies on Mondays, Tuesdays, and Wednesdays and tells the truth on other days of the week. The Unicorn, on the other hand, lies on Thursdays, Fridays, and Saturdays, but tells the truth on the other days of the week.

One day, Alice met the Lion and the Unicorn resting under a tree. They made the following statements:

Alice must know: What day is it really?

Illustration by John Tenniel (public domain)