Time: Tuesdays and Thursdays 3:05PM–4:25PM

Room: TEP 1308

Instructor: Jonas Frey

Office Hour: Wednesdays 4:30–5:30 PM in Baker Hall BH148

TA: Fernando Larrain

Office Hour: Mondays 10:00–11:00 AM in Doherty Hall DH4302-A

- Here is the eleventh homework sheet, due December 2 at 11:59pm. Starred exercise(s) for 80-713 only!
- Here is the tenth homework sheet, due November 17 at 11:59pm. Starred exercise(s) for 80-713 only!
- Here is the ninth homework sheet, due November 10 at 11:59pm. Starred exercise(s) for 80-713 only!
- Here is the eighth homework sheet, due November 3 at 11:59pm. Starred exercise(s) for 80-713 only!
- Here is the seventh homework sheet, due October 27 at 11:59pm. Starred exercise(s) for 80-713 only!
- Here is the sixth homework sheet, due October 20 at 11:59pm. Starred exercise(s) for 80-713 only!
- Here is the fifth homework sheet, due October 13 at 11:59pm. Starred exercise(s) for 80-713 only!
- Here is the fourth homework sheet, due October 6 at 11:59pm. Starred exercise(s) for 80-713 only!
- Here is the third homework sheet, due September 28 at 11:59pm. Starred exercise(s) for 80-713 only!
- Here is the second homework sheet, due September 21 at 11:59pm. Starred exercise(s) for 80-713 only!
- Here is the first homework sheet, due September 14 at 3pm. The last exercise with the star is for 80-713 only!
- Sign up to piazza using this link.
- Homeworks and announcements will be posted here.
- Feel free to email me if you have questions about the course or are unsure if it is for you.

Category theory is a formal discipline developed to study complex problems in algebra and geometry, and later applied in logic, physics, computer science and many other areas. As such, this course will be more like a math class than a typical philosophy section. In particular, students will be expected to provide formal arguments and proofs for homework and on tests.

At the same time, the course is relevant to a wide range of disciplines, so some students may be less conversant in mathematical jargon. For anyone that might be having trouble, here is a short how-to and here is a longer guide . Many more resources are easily available.

Steve Awodey, *Category Theory*, 2^{nd} edition,
Oxford University Press, 2010.

We will follow the book quite closely, taking about one week for each chapter.

- Emily Riehl,
*Category Theory in Context,*Courier Dover Publications, 2017. - Saunders Mac Lane,
*Categories for the Working Mathematician*, 2^{nd}edition, Springer, 1998. - F. William Lawvere and Stephen Schanuel,
*Conceptual Mathematics: a first introduction to categories,*2^{nd}edition, Cambridge University Press, 2009. - Tom Leinster,
*Basic Category Theory*, Cambridge University Press, 2014. - David Spivak,
*Category Theory for the Sciences*, The MIT Press, 2014. - The
*n*Lab: a wiki-lab on Mathematics, Physics and Philosophy from the point of view of (higher) category theory. They have pages on most concepts in our course and many beyond. - Category Theory: the entry at the Stanford Encyclopedia of Philosophy by Jean-Pierre Marquis discusses the history and philosophical significance of Category Theory.

- Homework: 64% = 8% times the sum of the best 8 homework scores (out of 10 sets) (to be revised)
- Final: 36%

Homework sets will typically consist of 3-5 problems, and will be posted here each week. Solutions to all problems should be written out in full sentences and paragraphs. See here if you have questions about writing up solution sets. In your solutions, you may appeal to any fact which has been proved either in class or in the course textbook.

~~Homework is due at the beginning of class on the due date
indicated on top. Late homework will not be accepted. E-mail
submission (~~
*PDF files only*) is preferred for LaTeX
solutions, and counts as a timestamp. To account for illness or
unforeseen personal circumstances, only the best 8 scores count
toward the grade.

Homework has to be submitted via gradescope, by the time indicated on the homework sheet.

The final will take place on Friday December 10 from 5:30PM to 8:30PM.

The undergraduate and graduate sections of this course will be taught together. However, students enrolled in the graduate section will be expected to work a little bit harder. Each homework set will contain 1-2 starred problems that only the 80-713 students will be expected to solve. The tests may also have additional starred problems.

Students are encouraged to write their assignments in LaTeX. The Wikibook on LaTeX is a good place to start. We recommend using the tikz-cd package for creating commutative diagrams; see the manual for details. You will need an up-to-date installation of TeX Live to take advantage of the newest version of tikz-cd.