1. Chan Hong-Mo and H. Høgaasen, Phys. Lett. 72B (1977) 121; Nucl. Phys. B136 (1978) 401.
2. R.L. Jaffe, Phys. Rev. D17 (1978) 1444.
3. This is a paraphrase of an argument given by R.L. Jaffe in a conversation with the author over coffee.
4. ; see also Chan Hong-Mo, Proc. of the XIX.International Conference on High Energy Physics, Tokyo (1978).
5. A. de Rujula, H. Georgi and S.L. Glashow, Phys. Rev. D12 (1975) 147.