2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/74899A natural Hasse-Schmidt derivation on the exterior algebra of a free module realizes the (small quantum) cohomology ring of the grassmannian $G_k(\CC^n)$ as a ring of operators on the exterior algebra of a free module of rank $n$. Classical Pieri's formula can be interpreted as Leibniz's rule enjoyed by special Schubert cycles with respect to the wedge product.To appear on Asian Journal of MathematicsAlgebraic Geometry14M15; 14N15text