Two-volume introduction to formal logic. Volume I presents sentence logic and Volume II covers predicate logic and metatheory. Features easy-to-understand explanations and graded exercises.
It is a shame that this (and volume 1) are out of print. Possibly the best introduction to formal logic available. To hell with Mates, Goldfarb, etc. Teller is clear, concise, and he loves truth-trees. To this day, I preface every argument that I analyze with a quick Teller-esque truth-tree. Why waste time with truth-tables and coin-flips on natural deduction?
[Incidentally, if Edward Teller (Paul's dad) was the 'father of the hydrogen bomb', does that make Paul Teller the hydrogen bomb?....of logic?]