Yes, Peter, the course is over. I don't think "temporarily" is a good adverb to insert here. Sorry!

However, the book by Fong and Spivak is still there for you to read, along with Tai-Danae Bradley's excellent short book. I also have zillions of blog articles and papers on categories where the morphisms are diagrams, available here:

* [Network theory](

If you have questions, just email me.