2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/63426A transitive smooth action of a connected Lie group G on a manifold M is called almost primitive (resp. primitive) if G doesn't contain any proper subgroup (resp. any proper normal subgroup) whose induced action on M is transitive as well. The aim of the present work is to investigate some combinatory properties of symplectic actions of completely solvable Lie groups.33 pages, 4 figures, latexDifferential Geometry22E 25, 22E45, 53A10text