  Electroweak unification is implied by the local structure theorem of
distribution theory applied to the causal interval R=X-Z between two space-time
points X and Z. Taking R as generating function, the potentials of the
electromagnetic and weak interactions are obtained by applying the causal
d'Alembertian operator on R, and both potentials can be given a proper physical
interpretation provided all calculations are made in the context of nonlinear
generalized functions.
