CSCI 0220

Discrete Structures and Probability

CSCI 0220 meets Mondays, Wednesdays, and Fridays from 1:00 - 1:50 pm.

I don't know about you, but we're feeling 22! This class, offered during the spring semester at Brown University (and in the fall semester as well starting in Fall 2025), gives you the tools to explore interesting questions and convince yourself and others of their answers. You'll be introduced to new worlds of ideas and ways of thinking. We'll learn about Set Theory, Logic, Number Theory, Combinatorics, and Probability. If these topics sound unfamiliar, not to fear—you're in exactly the right place! This course assumes no prior experience with these topics.

Important info before the semester starts:

  • Exams are in person: Midterm on 3/17 and Final on 5/16
  • Lectures will be streamed and recorded; attendance is strongly encouraged but not required.
  • Attendance at weekly recitation sections is required.
This year, we're taking proofs to the Wild West!

For the spring 2025 semester, this class will be taught by professors Robert Lewis and Ellis Hershkowitz. If you need to email them, please use their shared inbox cs220-instructors@brown.edu.

Tumbleweed

Assignments

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Homework Template Released Due Solutions
HW0 - Jan 22 Jan 29 -
HW1 Overleaf Template Jan 30 Feb 5 -
HW2 - Feb 6 Feb 12 -
HW3 - Feb 13 Feb 21 -
HW4 - Feb 20 Feb 26 -
HW5 - Feb 27 Mar 5 -
HW6 - Mar 6 Mar 12 -
HW7 (SRC/Extra Credit) - Mar 13 Mar 21 -
HW8 - Mar 19 Apr 3 -
HW9 - Apr 2 Apr 9 -
HW10 - Apr 10 Apr 16 -
HW11 - Apr 21 TBD -
Recitation Template Released Solution
Recitation 1 Overleaf Template Jan 30 -
- - Feb 6 -
- - Feb 13 -
- - Feb 20 -
- - Feb 27 -
- - Mar 6 -
- - -
- - Mar 13 -
- - Apr 3 -
- - Apr 10 -
- - Apr 24 -
- - -

Lectures

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Lecture Date Topic Recording
1 Jan 22 Intro Video
2 Jan 24 Statements, Proofs, and Contradictions Video
3 Jan 27 Propositional Logic: Connectives, Truth Tables Video
4 Jan 29 Formal Proofs in Propositional Logic Video
5 Jan 31 Propositional Proofs and Validity Video
6 Feb 3 First Order Logic (Quantifiers) Video
7 Feb 5 Formal Proofs in FOL Video
8 Feb 7 Language of Set Theory Video
9 Feb 10 Proof about Sets Video
10 Feb 12 Binary Relations Video
11 Feb 14 Injectivity, Surjectivity, Bijectivity Video
- Feb 17 Long Weekend - NO CLASS -
12 Feb 19 More Properties of Relations Video
13 Feb 21 Induction Video
14 Feb 24 Induction Variants Video
15 Feb 26 Number Theory -- Division Video
16 Feb 28 Division Algorithm Video
17 Mar 3 Modular Arithmetic Video
18 Mar 5 Multiplicative Inverses Video
19 Mar 7 Number Theory in Lean Video
20 Mar 10 Message Passing, RSA Video
21 Mar 12 Encryption and Ethics Video
22 Mar 14 Intro to Counting Video
- Mar 17 MIDTERM - IN CLASS -
23 Mar 19 Division Rule and Subsets Video
24 Mar 21 Binomial Theorem, Inclusion-Exclusion Video
- Mar 24 Spring Recess - NO CLASS -
- Mar 26 Spring Recess - NO CLASS -
- Mar 28 Spring Recess - NO CLASS -
25 Mar 31 Pigeonhole Principle Video
26 Apr 2 Counting Trees Video
27 Apr 4 Intro to Probability Video
28 Apr 7 Probability and Independence Video
29 Apr 9 Random Variables, Expectation Video
- Apr 11 Slack day -
30 Apr 14 Conditional Expectation Video
31 Apr 16 Linearity of Expectation Video
32 Apr 18 Bayes' Rule Video
33 Apr 21 Variance Video
34 Apr 23 Induction and Proofs on Data Video
- May 16 FINAL EXAM - IN PERSON -

Calendar

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Resources

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Staff

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Instructors

Robert Y. Lewis
Ellis Hershkowitz

Head TAs

Amy Qiao
Christina Stepin
Ilija Ivanov
Justin Shin
Tyler Gurth

UTA-STAs

Laura Romig

UTAs

Adithya Sriram
Alyssa Sun
Cerulean Ozarow
Grant Landon
Ilan Brauns
Kristen Cai
Lukas Strelecky
Michael Sun
Moses Yang
Zachary Wang