  This note considers the finite linear independence of coherent systems. We
show by simple arguments that lattice coherent systems of amenable groups are
linearly independent whenever the associated twisted group ring does not
contain any nontrivial zero divisors. We verify the latter for discrete locally
indicable groups, which includes lattices in nilpotent Lie groups. For the
particular case of time-frequency translates of Euclidean space, our main
result recovers the Heil-Ramanathan-Topiwala (HRT) conjecture for subsets of
arbitrary lattices.
