Book recommendation for beginning statement logic?

Hello All,

I am preparing to study mathematical linguistics and I must first master elementary statement and predicate logic. I have absolutely no background in formal systems or logic, and I would need an introductory text that assumes no previous knowledge of such things. Can anyone recommend a book on this topic that (preferably) includes exercises and would cover at least the following points:

*Logic syntax and semantics

*Tautologies, contradictions, contingencies

*Natural deduction?

If possible, one available in pdf form would be wonderful!

Thank you very much in advance for any recommendations.

Recommendation: The Schaum's Outline of Logic

The Schaum's Outline of Logic covers all of those. I don't believe it uses the term "natural deduction", but it does develop a natural deduction system of deduction. I don't think it contains the term "contingency", but as soon as you talk about tautologies and contradictions, and realize some wffs in logic are neither tautologies nor contradictions, those wffs come as contingencies. The Schaum's Outline of Logic also has a lot of solved problems, making it excellent for self-study or beginning study.