  The purpose of this paper is to study microlocal conditions for inclusion
relations between the ranges of square systems of pseudodifferential operators
which fail to be locally solvable. The work is an extension of earlier results
for the scalar case in this direction, where analogues of results by L.
H\"ormander about inclusion relations between the ranges of first order
differential operators with coefficients in $C^\infty$ which fail to be locally
solvable were obtained. We shall study the properties of the range of systems
of principal type with constant characteristics for which condition (\Psi) is
known to be equivalent to microlocal solvability.
