2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/218364We prove a general combinatorial formula yielding the intersection number $c_{u,v}^w$ of three particular $Λ$-minuscule Schubert classes in any Kac-Moody homogeneous space, generalising the Littlewood-Richardson rule. The combinatorics are based on jeu de taquin rectification in a poset defined by the heap of $w$.50 pages, option showlabels removedAlgebraic GeometryCombinatoricstext