The new (Fall 2017) edition of Sets, Logic, Computation is now officially done and available on Amazon [CA] [UK] [DE]. The most recent changes are outlined in this previous post, but: sequent calculus! new proof of completeness! a chapter on how to do proofs!
![](https://i0.wp.com/openlogicproject.org/wp-content/uploads/2017/09/amazonslc.png?fit=696%2C534&ssl=1)