**Grigore Constantin Moisil** was a Romanian mathematician and computer scientist who worked in the fields of mathematical logic and differential equations.

- His parents, however, believed that someone as devoted to mathematics as Grigore was, surely must take up engineering.
- Moisil submitted his doctoral thesis Analytical Mechanics of Continuous Systems in 1929 and the examining committee was lead by Țițeica, with Pompeiu and other mathematicians also on the committee.
- Moisil then went to Paris to study for the year 1930-31 where he worked with a number of mathematicians including Élie Cartan and Jacques Hadamard.
- An important event in Moisil's mathematical life was when he read Van der Waerden's famous work Moderne Algebra which had been published in 1930.
- Before reading this work Moisil had worked on differential equations, the theory of functions and mechanics.
- Algebra was not the only new research topic for Moisil during these years, for he became interested in logic after reading a paper by Jan Łukasiewicz.
- However, it was in the paper Recherches sur les logiques non-chrysippiennes Ⓣ(Research on non-chrysippian logic) (1940) that Moisil first defined 3-valued and 4-valued Łukasiewicz algebras.
- These algebras are now called Łukasiewicz-Moisil algebras or L-M algebras.
- First we must comment on the title of this paper, in particular the term non-chrysippiennes used by Moisil in the title.
- Moisil feels that the strictest standpoint in classical (formal) logic is represented by Chrysippus rather than Aristotle.
- To show the breadth of Moisil's research, in 1940 he also published Sur les petits mouvements des corps élastiques Ⓣ(On the small movements of elastic bodies) and Sur les géodésiques des espaces de Riemann singuliers Ⓣ(On the surveying of singular Riemann spaces).
- A position of professor at Bucharest University became available in 1941 and Moisil put himself forward for the position.
- However, Vrănceanu, Barbilian and Miron Nicolescu also applied for the post and Moisil was the youngest of these four, very well qualified, applicants.
- Moisil approached the ministry of education explaining what a great opportunity it would be for mathematics in Romania if all of them were to be appointed as professors in Bucharest.
- It looks like a long shot, but Moisil must have known what he was doing for indeed the ministry of education appointed them all to chairs.
- Moisil took up his new professorship at Bucharest University at the start of the 1941-42 academic year.
- Through the 1950 Moisil applied his ideas to the theory of switching circuits.
- Among Moisil's other books we mention: Associated matrices of systems of partial differential equations.
- Moisil was also involved in the introduction of computers into Romania.
- Eight years after his death, the Faculty of Mathematics of Bucharest University organised a conference on 10 January 1981 on the occasion of Moisil's 75th birthday.
- Moisil was elected to the Romanian Academy of Sciences in 1948, the Academy of Sciences in Bologna and to the International Institute of Philosophy.

Born 10 January 1906, Tulcea, Romania. Died 21 May 1973, Ottawa, Canada.

View full biography at MacTutor

Origin Romania

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive