I won’t bore you by reviewing the crooked path by which we got here. But I’m steadily working on the draft second edition of my intro logic book, with a cheerier feeling about the project.

And I can now offer you — drumroll! — some excerpts from three chapters on a Fitch-style natural deduction system for propositional logic, covering the rules for conjunction, disjunction and negation (and outline soundness/completeness proofs). For copyright reasons, these *are* excerpts of a few pages here and there, rather in Google books style, so the text jumps forward a couple of times. But the pages should be enough for you to be able to tell if you are interested in seeing more!

If you *would* like to see these chapters in full, about forty reasonably polished pages, do please drop an email to the address on the top of the PDF. The understanding is that if you ask to see more, then you *won’t* put the chapters into general circulation, and you *will* try to give at least some minimal comments (and certainly let me know about any errors you spot). At this stage in the game, even an encouraging ‘looks pretty ok to me!’ is welcome and helpful.

Jan von PlatoChange disjunction for implication and you will get somewhere. There is no decent way of handling V in the linear format.