Logic Options, 2: Reprise

Having given the seminar, and also found out what Michael Potter was saying about related stuff in lectures, I’ve redone/expanded the stuff on natural deduction in my reading notes on Logical Options Sec. 1.5.

Each round of tinkering makes the notes a bit more stand-alone: so if a student who has been introduced to logic by trees wants to get a handle on how axiomatic systems, natural deduction systems, and sequent calculi work for propositional logic, then this stuff should be useful even if they never open Logic Options (if only because it is more expansive than Bell, DeVidi and Solomon, and also it shuffles the techno stuff about the soundness and completeness proofs for an axiomatic system to the end, rather than cluttering up the exposition of the key features of the various approaches).

I should say, though, that these notes are dashed off at great speed between a lot of other commitments, so there are no doubt typos/thinkos (which I’d of course be grateful to hear about!). Enjoy …