In 1912, as a student he visited the
University of Göttingen. He was a professor at the
University of Caen. He was an Invited Speaker of the
International Congress of Mathematicians in 1924 in
Toronto, in 1932 in
Zürich, and in 1936 in
Oslo. Named in his honor are
Janet bases, Janet sequences and a related algorithm in the theory of systems of partial differential equations. In 1926, he proved results that were later generalized by
John Forbes Nash Jr. in his
embedding theorem. In 1948, Janet was the president of the
Société Mathématique de France. He was a close friend of the mathematician
Ernest Vessiot. ==Selected publications==