Key points are not available for this paper at this time.
It is remarked that left-right symmetry of the starting gauge interactions is a "natural" symmetry if it is broken in no way except possibly by mass terms in the Lagrangian. The implications of this result for the unification of coupling constants and for parity nonconservation at low and high energies are stressed.
Mohapatra et al. (Thu,) studied this question.