The matrix Darboux-Toda mapping is represented as a product of a numbe
r of commutative mappings. The matrix Davey-Stewartson hierarchy is in
variant with respect to each of these mappings. We thus introduce an e
ntirely new type of discrete transformation for this hierarchy. The di
screte transformation for the vector nonlinear Schrodinger system coin
cides with one of the mappings under necessary reduction conditions. (
C) 1998 Published by Elsevier Science B.V.