Math 4135/5135, Introduction to Category Theory
Fall 2005
Peter Selinger

Course Information

See the Course Information Sheet.


Final Exam (posted Nov 25). According to the Registrar's webpage, our final exam will be on Wednesday, December 7, at 15:30, in the Dalplex.

Presentations (posted Nov 25). We will meet on Monday, Nov. 28, at 5pm in (or in front of) Chase 319.

Welcome to the course (Sep 13). This web page will contain updated information, such as homework assignments, reading material, etc.


  • Homework 1 (Sep 22). p.15 #2,3,4 (#5 extra work); p.18 #1,3.
  • Homework 2 (Sep 29). From notes: p.16 exercise; From textbook: p.19 #5, p.21 #1,3,4,6.
  • Homework 3 (Oct 6). 1. Prove that Cat has products. 2. Prove that Top (or your favourite concrete category) has products. 3. Characterize when a poset, regarded as a category, has products. 4. Characterize when a monoid, regarded as a category, has products. Can a finite monoid have products?
  • Homework 4 (Oct 13). Prove that Set has coequalizers.


  • Lecture Notes (updated Oct 18): [ps, pdf]
  • Midterm Answers (posted Nov 6): [ps, pdf]

To Peter Selinger's Homepage: [home]
Peter Selinger / Department of Mathematics and Statistics / Dalhousie University
selinger@mathstat.dal.ca / PGP key