2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/70456We define geometric/unipotent crystal structure on unipotent subgroups of semi-simple algebraic groups. We shall show that in $A_n$-case, their ultra-discretizations coincide with crystals obtained by generalizing Young tableaux.LaTeX 17 pagesQuantum AlgebraRepresentation Theorytext