We present a derivation of the general form of the scalar potential in
Yang-Mills theory of a non-commutative space which is a product of a
four-dimensional manifold times a discrete set of points. We show that
a non-trivial potential without flat directions is obtained after eli
minating the auxiliary fields only if constraints are imposed on the m
ass matrices utilised in the Dirac operator. The constraints and poten
tial are related to a prepotential function.