The Isle of Dreams
Some logic puzzles about the Isle of Dreams, based on those found in "The Lady or the Tiger?" by Raymond Smullyan.
I once dreamed there was a certain island called the Isle of Dreams. The inhabitants of this island dream quite vividly; indeed, their thoughts while asleep are as vivid as while awake. Moreover, their dreamlife has the same continuity from night to night as their waking life has from day to day. As a result, some of the inhabitants sometimes have difficulty in knowing whether they are awake or asleep at a given time.
There are 4 laws that can be deduced concerning the inhabitants of the island.