COMMENT: Reply to a comment by R Newton

Abstract

Following Newton's comment (see ibid., vol.5, p.437 (1989)), the author points out that: (1) the major contribution of his previous paper (see ibid., vol.4, p.549 (1988)) is the generalised fast Cholesky algorithm, not the integral equations; (2) the Marchenko integral equation is correct as written, but does not determine the scattered field; and (3) it is implicitly assumed that the regular solution exists. The last two points suggest that the generalised fast Cholesky algorithm may be the only viable solution to the non-local problem.