In mathematics, Schubert calculus is a branch of algebraic geometry introduced in the nineteenth century by Hermann Schubert, in order to solve various counting problems of projective geometry. Wikipedia

A branch of algebraic geometry Wikipedia Disambiguation

A branch of algebraic geometry concerned with solving certain types of counting problem in projective geometry; a symbolic calculus used to represent and solve such problems; (by generalisation) the enumerative geometry of linear subspaces; the study of analogous questions in generalised cohomology theories. Wiktionary