 He introduced several notations used to this day, for instance the integral sign , representing an elongated S, from the Latin word "summa", and the used for differentials, from the Latin word "differentia".Leibniz did not publish anything about his calculus until 1684.Leibniz expressed the inverse relation of integration and differentiation, later called the fundamental theorem of calculus, by means of a figure in his 1693 paper "Supplementum geometriae dimensoriae...".