This Demonstration provides a generator for certain logic puzzles. These puzzles are about an island of two tribes. When two inhabitants communicate to each other they tell the truth if and only if they belong to the same tribe. So if an inhabitant tells a statement to inhabitant , then we may conclude that ⇔ ⇔. Here means that the first inhabitant is from the first tribe (and ¬ means that he/she is from the second tribe).