Headline news. A third edition of *Introducing Category Theory* is now available (free PDF/cheap pbk). Info/link at https://www.logicmatters.net/categories

Please spread the word!
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There comes a tipping point, when the prospect of yet another round of proof-reading becomes intolerable and you think, dammit, the book as it is will now just have to do! So I have drawn a line, put the latest version online, set up the printing of a paperback, and will organize a hardback too.

I asked Gemini, Claude and ChatGPT whether the result should be deemed a ‘Revised second edition’ or a ‘Third edition’. I had inclined to the first option. But the original second edition is error-strewn just enough for me not want to students to use it any more. And the shared opinion of my wise friends is that, in such a case, it is good practice to signal that the old version has been not just polished but superseded by calling the new version a third edition. Who am I to disagree?

As I have said before, I should apologize for putting (partial or full) earlier versions of these notes out into the world as paperbacks in a half-baked state. But my excuse is that, with a major heart operation looming, and then its aftermath, I wanted to have something done, not knowing what the future would hold. Hopefully, this third edition can now rest in a stable state. And I can move on!

You can find the paperback on your local Amazon, with the ISBN 1068346728. The price remains within pennies/cents of the very minimum possible.