Problem book on functors and category theory?

Question

I am trying to find a book I saw many years ago at a university library. Unfortunately, I remember so little of the book that I haven't been able to effectively search. What I do recall is that:

• the book was like a problem book on functors and category theory
• the first few pages, iirc, had a dialogue between 2 people
• the hardcover I saw had a blue (green?) cover, and probably had around 200 pages.

Answer 1

https://www.springer.com/gp/book/9780817641863

You're welcome! (this is added just to reach 30 characters)