- Here is the lecture-by-lecture schedule from 2013.Fall · 2008.Fall · 2000.Spring
- Recordings of lectures can be found in the Media Gallery on the Canvas page for our class.
- The instructor’s lecture notes, organized by topic, are linked to in the table below.

ECS 20 Fall 2021 Lecture-by-Lecture Schedule

Lecture Topic
Week 0 Notes: Introduction. Example problems: (1) counting paths; (2) R(3,3); (3) shuffling cards
0W Sep 22 Introductory remarks and example problem (1)
0R Sep 23 Introductory remarks and problems (1), (2), (3)
0F Sep 24 Example problems (2), (3)
0U Sep 26 Sunday@4 Recitation. This week in review. Homework hints. LaTeX tutorial.
Week 1 Notes: Logic-I. Propositional logic. Circuits. Getting formal.
1M Sep 27 Complaining about the room. Boolean domain 𝔹. Basic operators. Truth tables. Circuits.
1T Sep 28 Boolean domain 𝔹. Basic operators. Truth tables. Circuits. WFFs. Truth assignments
1T Sep 28 Homework 1 due at 5 pm
1W Sep 29 More Boolean operators. De Morgan’s laws. Equivalence. WFFs and their semantics.
1R Sep 30 WFFs, ta's. BNF and grammars. Satisfiability, tautologies, equivalence. Addition Short-circuited evaluation
1F Oct 01 WFFs, now with BNF. Satisfiability, tautologies, equivalence. Addition circuit.
1U Oct 03 Sunday@4 Recitation
Week 2 Notes: Logic-II. Completeness, soundness, compactness. Quantifiers. Set theory.
2M Oct 04 Finish addition circuit. A formal system of logic. Completeness, soundness, compactness.
2T Oct 05 A formal system for Boolean logic. Completeness, soundness, compactness. Tiling the plane
2T Oct 05 Homework 2 due at 5 pm
2W Oct 06 Review of formal proofs. Completeness, soundness, compactness. Adding quantifiers, enlarging the syntax.
2R Oct 07 Adding quantifiers, enlarging the syntax. Elements of set theory.
2F Oct 08 Unnoticed things you encounter often. Review of first-order logic. Truth. Vocabulary of set theory.
2U Oct 10 Sunday@4 Recitation: Representing a tic-tac-toe position with Booleans. Practice with binary conversions.
Week 3 Notes: Sets. Operations on sets. Russell’s paradox. Important sets.
3M Oct 11 Set operations and identities, including De Morgan’s law. Russell’s paradox. Cross products. Binary strings.
3T Oct 12 Set operations and identities, including De Morgan’s law. Russell’s paradox. Cross products. Binary strings. ASCII
3T Oct 12 Homework 3 due at 5 pm
3W Oct 13 De Morgan’s. Binary strings. Bytes and words. Representing integers with 2’s complement, reals with IEEE floats.
3R Oct 14 Representing integers with two’s complement, reals with IEEE 754. Sets with an operation: groups.
3F Oct 15 No lecture: watch at least 56:00-end of Lecture 3R. Online office hours in lieu of lecture.
3U Oct 17 Sunday@4 Recitation
Week 4 Sets, continued. Languages, regular languages. Notes: relations and functions
4M Oct 18 Cross product (n-fold). Strings, concatenation, languages. Relations. Equivalence relations
4T Oct 19 Cross product (n-fold). Strings, concatenation, languages. Regular languages. Relations. Equivalence relations
4T Oct 19 Homework 4 due at 5 pm
4W Oct 20 Strings, concatenation, languages. The star operator. Regular languages. The Chomsky hierarchy
4R Oct 21 Review relations, equivalence relations. Functions. 1-to-1 and onto. ZF(C). Poem. Number your days
4F Oct 22 Review relations, equivalence relations. Functions. 1-to-1 and onto.
4U Oct 24 Sunday@4 Recitation
Week 5 Functions, cont. Equinumerous sets. Induction Notes: relations and functions
5M Oct 25 Composition. Func(A,B), Perm(A). Most functions can’t be computed. Symmetric group Sn
5T Oct 26 Composition. Inverses. Func(A,B). Most functions can’t be computed. Symmetric group Sn. Equicardinal sets.
5W Oct 27 Permutations. Iterating a function. Blockciphers. Giant cycles, rhos. Representing a point in Sn. Equicardinal sets
5W Oct 27 Homework 5 due at 5 pm
5W Oct 27 Midterm released at 5 pm
5R Oct 28 Equinumerous sets: ℕ, ℤ, ℚ. Diagonalization: the reals are uncountable. SB Theorem. Peano axioms. Induction
5F Oct 29 Equinumerous sets. Diagonalization: the reals are uncountable. Peano axioms
5F Oct 29 Midterm due at 5 pm
5U Oct 31 Sunday@4 Recitation
Week 6 Going over MT. Number theory. Induction. Notes: numbers and induction
6M Nov 01 Went over midterm questions. Concretized what is “practical”.
6T Nov 02 Went over midterm questions. Concretized what is “practical”. Number theory. Induction. The sum Sn=1+2+...+n.
6W Nov 03 Types of induction. Various examples: sum#1, sum#2. The Fund Thm of Arith.
6W Nov 03 Homework 6 due at 5 pm
6R Nov 04 More induction: sum of first n odds; n2 + n is even; Fund Thm of Arith; triominoe tiling; dispensing envelopes.
6F Nov 05 More induction: Fund Thm of Arith; dispensing envelopes; n2 + n is even.
6U Nov 07 Sunday@4 Recitation
Week 7 Number theory. Induction. Notes: numbers (part 2)
7M Nov 08 Triomino tiling. Well-ordering. Division Theorem. Different views of mod. Euler&rsquop;s algorithm for the gcd.
7T Nov 09 Well-ordering. Division Theorem. Different views of mod. Euler’s algorithm. The group ℤn*. DH key exchange.
7W Nov 10 Lagrange's Thm. Fermat's Little Thm. The group ℤn*. DH key exchange.
7W Nov 10 Homework 7 due at 5 pm
7R Nov 11 Holiday (Veterans Day) — no class
7F Nov 12 Move day. Here is the annotated list of films screened. Make sure you understand the third problem.
7U Nov 14 Sunday@4 Recitation
Week 8 Recursion, recurrence relations, and asymptotics. Notes: recursion Notes: asymptotics.
8M Nov 15 Mystery metal object. Num of tic-tac-toe games. Towers of Hanoi puzzle.
8T Nov 16 Num of tic-tac-toe games. Towers of Hanoi. Recurrence relations. Karatsuba multiplication. Big-O.
8W Nov 17 Karatsuba’s algorithm. Solving recurrences. Big-O notation.
8W Nov 17 Homework 8 due at 5 pm
8R Nov 18 Big-O, Ω, and Θ. Recursion trees. Binary search. Mergesort. Calculating partition numbers.
8F Nov 19 Big-O, Ω, and Θ. Recursion trees. Binary search. Mergesort.
8U Nov 21 Sunday@4 Recitation
Week 9 Counting and a touch of probability. Notes: counting. Notes: probability.
9M Nov 22 P(n,k) and C(n,k). Sum rule, product rule, inclusion/exclusion. Practice counting.
9T Nov 23 Sum rule, product rule, inclusion/exclusion. Practice counting. Probability calculations.
9W Nov 24 More practice counting. More fighting with the microphone that hates me. Probability basics.
9W Nov 24 Homework 9 due at 5 pm
9R Nov 25 Holiday (Thanksgiving) (You don’t really want to kill/eat any abused animals, do you?)
9F Nov 26 Holiday (Thanksgiving)
9U Nov 28 Sunday@4 Recitation is moved to Monday@5 this week
Week 10 Probability. PHP. Graphs. Notes: probability. Notes: pigeonhole principle. Notes: graph theory..
10M Nov 29 Probability spaces, events, RVs, expectation. Examples.
10M Nov 29 Monday@5 Recitation
10T Nov 30 (1) Probability spaces, events, RVs, expectation. Birthday surprise. Let’s Make a Deal. (2) Pigeonhole principle.
10W Dec 01 Review of probability basics. Birthday surprise. Monty Hall problem. Pigeonhole principle and examples.
10R Dec 02 Homework 10 due at 11 am
10R Dec 02 Another PHP example. Graph theory basics. Concluding remarks.
10F Dec 03 Graph theory basics (isomorphism, Eulerian & Hamiltonian graphs, colorability). Concluding remarks.
10S Dec 04 1pm Zoom-based review session. Try to do the final exam first.
Week 11 Finals week
Mon Dec 06 1pm Final for Section B (TR). Wellman 106 and Wellman 226
Fri Dec 10 8am Final for Section A (MWF). Wellman 1 (A-H), Wellman 25 (I-L), and Wellman 6 (M-Z)