 Frege's propositional calculus

In mathematical logic, Frege's propositional calculus was the first axiomatization of propositional calculus.It was invented by Gottlob Frege, who also invented predicate calculus, in 1879 as part of his second-order predicate calculus (although Charles Peirce was the first to use the term "second-order" and developed his own version of the predicate calculus independently of Frege).