How to Make an Introductory Class in Set Theory and Logic Exciting I am teaching a "proof techniques" class for sophomore math majors.  We start out defining sets and what you can do with them (intersection, union, cartesian product, etc.).  We then move on to predicate logic and simple proofs using the rules of first order logic.  After that we prove simple math statements via direct proof, contrapositive, contradiction, induction, etc. Finally, we end with basic, but important concepts, injective/surjective, cardinality, modular arithmetic, and relations.
I am having a hard time keeping the class interested in the beginning set theory and logic part of the course.  It is pretty dry material.  What types of games or group activities might be both more enjoyable than my lectures and instructive?

maybe start with some riddles from http://en.wikipedia.org/wiki/Charles_Lutwidge_Dodgson or http://en.wikipedia.org/wiki/Raymond_Smullyan both have made books full with logical riddles
