forall x: An Introduction to Formal Logic

# forall x: An Introduction to Formal Logic

forall x is an open access introductory textbook in formal logic. It covers translation, proofs, and formal semantics for sentential and predicate logic. forall x was written by P.D. Magnus, an associate professor at the University at Albany, State University of New York.

What is logic?

1.1 Arguments .

1.2 Sentences .

1.3 Two ways that arguments can go wrong

1.4 Deductive validity .

1.5 Other logical notions .

1.6 Formal languages

2 Sentential logic

2.1 Sentence letters .

2.2 Connectives .

2.3 Other symbolization

2.4 Sentences of SL

3 Truth tables

3.1 Truth-functional connectives .

3.2 Complete truth tables

3.3 Using truth tables .

3.4 Partial truth tables .

4 Quantified logic

4.1 From sentences to predicates

4.2 Building blocks of QL .

4.3 Quantifiers .

4.4 Translating to QL

4.5 Sentences of QL

4.6 Identity

5 Formal semantics

5.1 Semantics for SL

CONTENTS

5.2 Interpretations and models in QL

5.3 Semantics for identity

5.4 Working with models .

5.5 Truth in QL

Practice Exercises

6 Proofs

6.1 Basic rules for SL .

6.2 Derived rules .

6.3 Rules of replacement

6.4 Rules for quantifiers

6.5 Rules for identity

6.6 Proof strategy

6.7 Proof-theoretic concepts

6.8 Proofs and models

6.9 Soundness and completeness