  We study the topological heterotic ring in (0,2) Landau-Ginzburg models
without a (2,2) locus. The ring elements correspond to elements of the Koszul
cohomology groups associated to a zero-dimensional ideal in a polynomial ring,
and the computation of half-twisted genus zero correlators reduces to a map
from the first non-trivial Koszul cohomology group to complex numbers. This map
is a generalization of the local Grothendieck residue. The results may be
applied to computations of Yukawa couplings in a heterotic compactification at
a Landau-Ginzburg point.
