Abstract
The general matrix Schrodinger problem is studied and the corresponding equations for the inverse scattering method are obtained. Appropriate modifications lead to a derivation of the generalised Gel'fand-Levitan-Marchenko equations for the case in which there are double poles of the matrix A-1(k). The symplectic structure associated with the non-linear evolution equations of this formalism is also investigated. Special attention is paid to the derivation of the Poisson bracket of the reflection coefficients.