“…Observe that the Jacobian matrix of the right-hand side of (8) with respect to u(t) equals K (z(t),u(t)). So we may apply the implicit function theorem yielding locally u(t) as an analytic function of z(¢) and y (t + d 1),... ,yz],'/f(t + dp), i.e., u(t) = a(z(t),yl" (t + d 1),... , 4 (t + dp)) such that yi! (t + di) : = A(z(t), a(z(t),y (t+dl),---»y 7 (t+dp))).…”