Thursday, February 15, 2001
An argument is (deductively) valid, if it is logically impossible for the premises to be true and the conclusion false at the same time. (Lecture).
An argument is sound if it is valid and its premises are true (Lecture).
Propositions (statements, declarative sentences) (Lecture).
Number theory, set theory, utility theory, physics, and many more (Lecture).
If it is not possible to derive a contradiction from the axioms (Lecture).