 What is now a commonplace treatment of quantification began with Frege (1879), where the German philosopher and mathematician, Gottlob Frege, devised a formal language equipped with quantifier symbols, which bound different styles of variables. He formulated axioms and rules of inference, which allowed him to represent a remarkable range of mathematical argumentation. Classical quantificational logic is sometimes known as “first-order” or “predicate” logic, which is generally taken to include functional and constant symbols. The vocabulary of classical quantificational logic is often supplemented with an identity predicate to yield the classical theory of quantification with identity.