The group inverse L# of the Sylvester transformation L(X) = AX - XB is
(provided that it exists) represented in polynomial form L#(Y) = Sigm
a(ij)c(ij)A(i)YB(j) in terms of the minimal polynomials of A and B. In
one of the representations the coefficient matrix [c(ij)] is expresse
d with the help of a new class of ''derived'' Hankel matrices. (C) Els
evier Science Inc., 1997.