Obtaining the Gauge Invariant Kinetic Term for a SU(n)_U x SU(m)_V Lagrangian

We propose a generalized way to formally obtain the gauge invariance of the kinetic part of a field Lagrangian over which a gauge transformation ruled by an $SU(n)_{U} \otimes SU(m)_{V}$ coupling symmetry is applied. As an illustrative example, we employ such a formal construction for reproducing the standard model Lagrangian. This generalized formulation is supposed to contribute for initiating the study of gauge transformation applied to generalized $SU(n)_{U} \otimes SU(m)_{V}$ symmetries as well as for complementing an introductory study of the standard model of elementary particles.