1st Edition

An Introduction to Mathematical Proofs

By Nicholas A. Loehr Copyright 2020
412 Pages 67 B/W Illustrations
by CRC Press

412 Pages 67 B/W Illustrations
by CRC Press

412 Pages 67 B/W Illustrations
by CRC Press

An Introduction to Mathematical Proofs presents fundamental material on logic, proof methods, set theory, number theory, relations, functions, cardinality, and the real number system. The text uses a methodical, detailed, and highly structured approach to proof techniques and related topics. No prerequisites are needed beyond high-school algebra. New material is presented in small chunks... Read more

Logic



Propositions; Logical Connectives; Truth Tables



Logical Equivalence; IF-Statements



IF, IFF, Tautologies, and Contradictions



Tautologies; Quantifiers; Universes



Properties of Quantifiers: Useful Denials



Denial Practice; Uniqueness





Proofs



Definitions, Axioms, Theorems, and Proofs



Proving Existence Statements and IF Statements



Contrapositive Proofs; IFF Proofs



Proofs by Contradiction; OR Proofs



Proof by Cases; Disproofs



Proving Universal Statements; Multiple Quantifiers



More Quantifier Properties and Proofs (Optional)





Sets



Set Operations; Subset Proofs



More Subset Proofs; Set Equality Proofs



More Set Quality Proofs; Circle Proofs; Chain Proofs



Small Sets; Power Sets; Contrasting ∈ and ⊆



Ordered Pairs; Product Sets



General Unions and Intersections



Axiomatic Set Theory (Optional)





Integers



Recursive Definitions; Proofs by Induction



Induction Starting Anywhere: Backwards Induction



Strong Induction



Prime Numbers; Division with Remainder



Greatest Common Divisors; Euclid’s GCD Algorithm



More on GCDs; Uniqueness of Prime Factorizations



Consequences of Prime Factorization (Optional)





Relations and Functions



Relations; Images of Sets under Relations



Inverses, Identity, and Composition of Relations



Properties of Relations



Definition of Functions



Examples of Functions; Proving Equality of Functions



Composition, Restriction, and Gluing



Direct Images and Preimages



Injective, Surjective, and Bijective Functions



Inverse Functions





Equivalence Relations and Partial Orders



Reflexive, Symmetric, and Transitive Relations



Equivalence Relations



Equivalence Classes



Set Partitions



Partially Ordered Sets



Equivalence Relations and Algebraic Structures (Optional)





Cardinality



Finite Sets



Countably Infinite Sets



Countable Sets



Uncountable Sets





Real Numbers (Optional)



Axioms for R; Properties of Addition



Algebraic Properties of Real Numbers



Natural Numbers, Integers, and Rational Numbers



Ordering, Absolute Value, and Distance



Greatest Elements, Least Upper Bounds, and Completeness





Suggestions for Further Reading

Biography

Nicholas A. Loehr is an associate professor of mathematics at Virginia Technical University. He has taught at College of William and Mary, United States Naval Academy, and University of Pennsylvania. He has won many teaching awards at three different schools. He has published over 50 journal articles. He also authored three other books for CRC Press, including Combinatorics, Second Edition, and Advanced Linear Algebra.