2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/122866Let G be a Lie groupoid with Lie algebroid g. It is known that, unlike in the case of Lie groups, not every subalgebroid of g can be integrated by a subgroupoid of G. In this paper we study conditions on the invariant foliation defined by a given subalgebroid under which such an integration is possible. We also consider the problem of integrability by closed subgroupoids, and we give conditions under which the closure of a subgroupoid is again a subgroupoid.Differential GeometrySymplectic Geometry22A22; 22E60; 58H05text