2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/195012Quantization of a Lagrangian field system essentially depends on its degeneracy and implies its BRST extension defined by sets of non-trivial Noether and higher-stage Noether identities. However, one meets a problem how to select trivial and non-trivial higher-stage Noether identities. We show that, under certain conditions, one can associate to a degenerate Lagrangian L the KT-BRST complex of fields, antifields and ghosts whose boundary and coboundary operators provide all non-trivial Noether identities and gauge symmetries of L. In this case, L can be extended to a proper solution of the master equation.15 pages, accepted for publication in Lett. Math. PhysMathematical PhysicsDifferential Geometry58A20; 58C50; 70S05; 70S20text