So, at long last, a full draft of *Category Theory I* is online.

There are now thirteen added pages of content, plus an index of definitions. The main substantive change is the added last chapter on ‘the elementary theory of the category of sets’.

I’ll draw breath, do a quick-ish end-to-end read for consistency, and aim to get a print-on-demand paperback set up by the end of the month. That won’t be to fix the text once and for all: I’m thinking of this as a beta version, and an easily revisable paperback will just be there for those (including me!) who find a 228 page printed book easier to work from and comment on than an onscreen PDF.

Of course (and you know what’s coming next, because I’ve said it before), if you have been meaning to drop me a note with comments/suggestions/corrections, then now — yes, really now — is the time to do so!

Current versions of *Category Theory I* and *II* can be downloaded here.

*Updated Jul 17*: Revised version with a few very minor corrections to pp.1-100.

TTHello, professor, do you have the plan to revise category theory II?

Peter SmithShort answer, yes! Starting in a couple of months, I hope.