Illness (not so great) followed by fortnight’s holiday (really excellent) stopped work on category theory for a while. Very slowly getting back to it. But in the meantime, a number of people have very kindly been sending corrections to the last version of the Notes. I have also tinkered in minor ways, improving the last chapter in particular. There are just about enough changes to warrant another “maintenance upgrade”, making some of the needed repairs and improvements.

I hope to have a couple more chapters on adjoints ready for prime time later in the month — but finding a neat expository path through the material is a challenge, so don’t hold your breath!

The plan at the moment is for another five or six more chapters in total to round off Part I of these Notes, on basic category theory (I’m not sure yet whether I also need to say anything about monads for what is going to follow). And then — having got the bit between my teeth — I’d like to continue, by discussing some logic and set theory in a categorial way in Part II of the Notes. Promises, promises.