2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/88862A demonstration is given that the simplest model of quantum mechanics formulated on a plane non-commutative geometry endowed with a Galilean symmetry group in which the position and linear momentum-variable commutators are first order in the dynamical variables (and thus constitute a true Lie algebra) is incompatible with the hypothesis of spacial isotropy.12 pages, no figuresQuantum Physicstext