>>15464668

I'm not sure what to recommend. I have a severe distaste for the way the discipline is treated, anyway. apparently people use the term 'valid proof' in a loose manner to mean all sorts of vague but encouraging things about a proof but the definition I grew up with was 'a proof consisting of correct inference steps only', so e.g. it should not contain a reasoning step of the form A implies B therefore not A implies not B. but you can start from any axioms, loony or otherwise, or you can assume your conclusion as an axiom, and validity would not be impacted. you can have a valid proof proving ridiculous garbage, but it must do so through correct steps.

as for modal logic, which gödel used, I think it is mere wanking. it can be restated in plain logic, but its adherents wave it around as if it was this super-powerful tool.

tldr I hate philosophers.