2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/140219The goal of this paper is to present a modified version (GML) of ML invariant which should take into account rulings over a projective base and allow further stratification of smooth affine rational surfaces. We provide a non-trivial example where GML invariant is computed for a smooth affine rational surface admitting no C-actions. We apply GML invariant to computation of ML invariant of some threefolds.21 pages, LaTexAlgebraic Geometry14ER05, 14R25text