Math 3345: Lecture Notes

Sections 26965 & 26980
Spring 2023
Max Kutler

These notes are the basis for our Math 3345 lectures. There may be material discussed in class which is not included in these notes, and vice versa.



Lecture 1: Logical sentences, negation, conjunction

Lecture 2: Disjunction, De Morgan's laws

Lecture 3: Distributive laws, implication

Lecture 4: Conditional and biconditional sentences, converse and contrapositive

Lecture 5: Conditional proof, tautologies

Lecture 6: Quantifiers

Lecture 7: Generalized De Morgan and distributive laws

Lecture 8: Order of quantifiers, unique existence

Lecture 9: Induction

Lecture 10: More induction, parity

Lecture 11: Axioms for the integers (also see the Integers handout)

Lecture 12: Some basic consequences of the integer axioms

Lecture 13: Positive integers and the well-ordering principle

Lecture 14: Divisibility

Lecture 15: Primes

Lecture 16: The infinitude of primes

Lecture 17: Division Algorithm

Lecture 18: Greatest common divisors, Euclidean Algorithm

Lecture 19: Reverse Euclidean Algorithm, congruence of integers

Lecture 20: Modular arithmetic

Lecture 21: The Fundamental Theorem of Arithmetic

Lecture 22: Theorem on division by a prime, applications of FTA

Lecture 23: Proof of FTA

Lecture 24: Real and rational numbers

Lecture 25: Irrational numbers

Lecture 26: Square roots of integers, intro to sets

Lecture 27: Sets, subsets

Lecture 28: Algebra of sets, DeMorgan's laws for sets

Lecture 29: Sets of sets, generalized unions and intersections, power sets, ordered pairs

Lecture 30: Cartesian products, functions

Lecture 31: Graphs, function composition

Lecture 32: Surjections, injections, bijections

Lecture 33: Inverse functions

Lecture 34: Cardinality

Lecture 35: Finite sets, pigeonhole principle

Lecture 36: Infinite sets, countability

Lecture 37: Uncountability of R