the formula remains valid. Later in his career, Demazure's research emphasis shifted from pure mathematics to more computational problems, involving the application of algebraic geometry to image reconstruction problems in computer vision. The Kruppa–Demazure theorem, stemming from this work, shows that if a scene consisting of five points is viewed from two cameras with unknown positions but known focal lengths then, in general, there will be exactly ten different scenes that could have generated the same two images. Austrian mathematician Erwin Kruppa had many years earlier narrowed the number of possible scenes to eleven, and Demazure provided the first complete solution to the problem. Books Schémas en groupes. I: Propriétés générales des schémas en groupes (SGA3, vol. I, with Grothendieck). Lecture Notes in Mathematics 151, Berlin: Springer-Verlag, 1970. . Schémas en groupes. II: Groupes de type multiplicatif, et structure des schémas en groupes généraux (SGA3, vol. II, with Grothendieck). Lecture Notes in Mathematics 152, Berlin: Springer-Verlag, 1970. . Schémas en groupes. III: Structure des schémas en groupes réductifs (SGA3, vol. III, with Grothendieck). Lecture Notes in Mathematics 153, Berlin: Springer-Verlag, 1970. . Groupes algébriques. Tome I: Géométrie algébrique, généralités, groupes commutatifs (with Pierre Gabriel). Masson, Amsterdam: North Holland, 1970. . Partially translated into English by J. Bell as Introduction to Algebraic Geometry and Algebraic Groups, Volume 39 of North-Holland Mathematics Studies, Elsevier, 1980, . Lectures on p-divisible groups. Lecture Notes in Mathematics 302, Berlin: Springer-Verlag, 1972, 1986, . , . Bifurcations and catastrophes: Geometry of solutions to nonlinear problems. Universitext, Berlin: Springer-Verlag, 2000. Translated from the French (1989) by David Chillingworth. . Cours d'Algèbre: Primalité. Divisibilité. Codes. Paris: Cassini, 1997, 2008. . References 1937 births Living people École Normale Supérieure alumni Algebraic geometers 20th-century French mathematicians 21st-century French mathematicians University of Paris alumni Nicolas Bourbaki