  Starting from a simple discrete model which exhibits a supersymmetric
invariance we construct a local, interacting, two-dimensional Euclidean lattice
theory which also admits an exact supersymmetry. This model is shown to
correspond to the Wess-Zumino model with extended N=2 supersymmetry in the
continuum. We have performed dynamical fermion simulations to check the
spectrum and supersymmetric Ward identities and find good agreement with
theory.
