PEANO, GIUSEPPE

born Aug. 27, 1858, Cuneo, Sardinia died April 20, 1932, Turin, Italy Italian mathematician and a founder of symbolic logic whose interests centred on the foundations of mathematics and on the development of a formal logical language. He became a lecturer of infinitesimal calculus at the University of Turin in 1884 and professor in 1890. He also held the post of professor at the Accademia Militare, Turin, from 1886 to 1901. His Formulaire de mathematiques (Italian Formulario Mathematico; Mathematical Formulary), published 1894 to 1908 with collaborators, was intended to develop mathematics in its entirety from its fundamental postulates using Peano's logic notation. This work, and others, profoundly changed the outlook of mathematicians and was a major influence upon later efforts to restructure mathematics, notably the program by the French mathematicians whose works appear under the pseudonym Nicolas Bourbaki. Part of Peano's logic notation was adopted by Bertrand Russell and Alfred North Whitehead in their Principia Mathematica, 3 vol. (191013). Peano's Calcolo differenziale e principii di calcolo integrale (1884; Differential Calculus and Principles of Integral Calculus) and Lezioni di analisi infinitesimale, 2 vol. (1893; Lessons of Infinitesimal Analysis) are two of the most important works on the development of the general theory of functions since the work of the French mathematician Augustin Cauchy (died 1857). In Applicazioni geometriche del calcolo infinitesimale (1887; Geometrical Applications of Infinitesimal Calculus) Peano introduced the basic elements of geometric calculus and gave new definitions for the length of an arc and for the area of a curved surface. Calcolo geometrico (1888; Geometric Calculus) contains his first work on mathematical logic. Peano is also known as the creator of Latino sine Flexione, later called Interlingua, an artificial language. Based upon a synthesis of the vocabulary from Latin, French, German, and English, with a greatly simplified grammar, Interlingua was intended for use as an international auxiliary language. Peano compiled a Vocabulario de interlingua (1915) and was for a time president of the Academia pro Interlingua.