Some axioms are definitions.
Previous theorem: All unmarried men are not married New definition: “Bachelor” means “unmarried man” New theorem: All bachelors are unmarried men.
I’m pretty sure that’s what he means. Hopefully clarified, if not made perfectly in accord with standard definitions.
I’m pretty sure that’s what he means.
I think that he means something analogous to the way that we can add some axioms involving the symbol “+” to the Peano axioms, and then show in second-order logic that the new axioms define addition uniquely.
Some axioms are definitions.
Previous theorem: All unmarried men are not married New definition: “Bachelor” means “unmarried man” New theorem: All bachelors are unmarried men.
I’m pretty sure that’s what he means. Hopefully clarified, if not made perfectly in accord with standard definitions.
I think that he means something analogous to the way that we can add some axioms involving the symbol “+” to the Peano axioms, and then show in second-order logic that the new axioms define addition uniquely.