Logic & Mathematics

• Valid argument - An argument is valid when it contains no logical fallacies
• Sound argument - an argument that is valid and whose premises are all true. In other words, the premises are true and the conclusion necessarily follows from them, making the conclusion true as well.
• Formal proof - A set of steps from axiom(s) and previous proof(s) which follows the rules of induction of a mathematical system.
Applied to Is LessWrong dead without Cox’s theorem? by [anonymous] at 1mo
Applied to The case for hypocrisy by aaronb50 at 5mo