How to Prove It
Daniel J. Velleman
Start here, even if you think you are past it. Most people arriving at higher mathematics have spent years computing answers and almost no time justifying them, and the gap between those two activities is the whole subject. Velleman closes it deliberately. He builds the machinery of proof from the logic up, beginning with quantifiers and the anatomy of an implication, then showing how a definition quietly contains the strategy for proving things about it. By the end you are not memorizing proof templates. You are reading a statement and seeing, almost automatically, what its first line must be.
It also does double duty as a gentle introduction to logic, which everything later on this map silently assumes you already have. Work the exercises in writing, not in your head — this is the one book here where reading passively is reading wasted, because the skill being taught is a physical habit of the hand as much as the mind. Give it a month of real attention and the rest of the climb changes character. Definitions stop feeling arbitrary, and proofs stop feeling like magic performed by other people.





































