Thorough, plain, succinct coverage -with plenty of detailed examples- of the wide variety of subjects that all fit under the umbrella "logic". My thought was both the content and the tone are similar to what I imagined a "Logic for Dummies" book would be like. It turns out that a "Logic for Dummies" book really does exist, and some of the reviews on Amazon really do say the two books are quite similar.
The one and only topic that I thought might be covered but that in fact was _not was "fuzzy logic". Maybe it's too arcane for succinct explanations, maybe this book predates the fashion (although based on publication dates I don't think so), or maybe "fuzzy logic" has already come _and _gone.
As a former computer programmer some of the material was very familiar to me. I felt I could do all the "boolean logic" stuff in my sleep; on the other hand Predicate Logic proofs still escape me despite the best efforts of the book.
Although the book _never _explicitly _says (in fact it makes _no "meta" comments at all), my own impression from reading the book's various chapters is that historically several different systems of logic developed and they all still exist, that these various threads use similar (but not identical) notations and concepts, and that the choice of which to use for what doesn't have a crisp answer because there's so much overlap.