Gottfried Wilhelm Leibniz (1646–1716) was a German philosopher and mathematician. In mathematics, several results and concepts are attributed to Leibniz: * Leibniz algebra, an algebraic structure * Leibniz formula for π, an inefficient method for calculating π * Leibniz formula for determinants, an expression for the determinant of a matrix * Leibniz integral rule, a rule for differentiation under the integral sign * Leibniz's notation, a notation in calculus * Leibniz operator, a concept in abstract logic * Leibniz law, see product rule of calculus * General Leibniz rule, a generalization of the product rule * Alternating series test, also known as Leibniz's test or Leibniz's rule