Complex sentence: In the 1960s, Demazure was a student of Alexandre Grothendieck, and together with Grothendieck he ran and edited the Séminaire de Géométrie Algébrique du Bois Marie on group schemes at the Institut des Hautes Études Scientifiques near Paris from 1962 to 1964.
Split into simpler sentences: In the 1960s, Demazure was a student of Alexandre Grothendieck. They ran the Séminaire de Géométrie Algébrique du Bois Marie on group schemes at the Institut des Hautes Études Scientifiques near Paris from 1962 to 1964.