ezyang’s blog

the arc of software bends towards understanding

Visualizing satisfiability, validity & entailment

So you’re half bored to death working on your propositional logic problem set (after all, you know what AND and OR are, being a computer scientist), and suddenly the problem set gives you a real stinker of a question: Is it true that Γ ⊢ A implies that Γ ⊢ ¬A is false? and you […]

  • October 15, 2012