A matrix A is said to possess a displacement structure if the rank of
del(A) := AU - VA is smalled compared with the order of A. In the note
the problem is raised to which extend well-known theory and algorithm
s for matrices with a displacement structure can be generalized to mat
rices A for which the rank of del(m)(A) is small for m > 1. (C) 1998 E
lsevier Science Inc. All rights reserved.