Let Q c ƒ?", n ^ 2, be a bounded open set with boundary dQ a regularly imbedded C 00 submanifold of R n . Let a(y; £, X) be the polynomial Let a 0 (y;^ X) be the principal part, the terms of total degree p. We assume that, for yeU^eR n 9 the roots of a 0 (y;^, •) are all real and nonzero. This implies p = 2r is even. Let b k (y\ Ç, X) be polynomials of order p k < p, k = 1,2, ...,r, with principal part b k0 (y; 0, or