Combinatorial Theory (Math 206A, Fall 2020)

Instructor: Igor Pak
(see email instructions on the bottom of the page).

CCLE Website: is here.

Class schedule: MWF 2:00 - 2:50 pm, via Zoom.
Zoom meeting link and password will be sent by email from the course my.ucla site.

Office Hours: M 3-4, via Zoom (stay after class).

Grading: The grade will be based on attendance, class participation (20%), and homeworks (80%) which will be posted below.

Difficulty: This is a graduate class in Combinatorics. Students are assumed to be fully familiar with undergraduate Combinatorics and Graph Theory (see Math 180 and Math 184).


Much of the course will be dedicated to the study of partially ordered sets, their properties, examples and many applications. We will follow various sections from the textbooks and surveys below.

Lecture notes: Will be posted on CCLE website if and when they come available.


These are very preliminary, the exact list will be updated and expanded weekly with specific sections indicated. Note: the readings not linked below will be available from the CCLE website (see "Additional Reading" section).


None of these are required, all are recommended. Selected relevant chapters will be posted on CCLE.



Lecture by lecture background reading

  1. Basic notions

  2. Dilworth's theorem (see West, Ch. 12)

  3. Gallai-Milgram theorem (see West, Ch. 12)

  4. Chains and antichains in the Boolean lattice

  5. Gray codes and universal sequences

  6. Extremal Combinatorics

  7. Perfect graphs (see Diestel, §5.5; see also earlier sections for notations and some background)

  8. Subsets of distinct numbers via Sperner's property (using LA, see Proctor's paper and Stanley's talk slides)

Home assignments

These will be posted here. The solutions will need to be uploaded to via Gradescope, which is also linked to the course CCLE website.

Collaboration policy:
For the home assignments, you can form discussion groups of up to 3 people each. In fact, I would like to encourage you to do that. You can discuss problems but have to write your own separate solutions. You should write the list of people in you group on top of each HA.

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Any and all grade discussion must be done from your official UCLA email. Enclose your UCLA id number and full name as on the id on the bottom.

Last updated 10/14/2020.