  The concepts of `conditional entropy' and `information' retain their validity
for quantum systems, but their properties differ somewhat from those of their
classical counterparts; specifically, some equalities and inequalities of
classical information theory are in general violated.
  In this paper the concepts are generalized to include arbitrary indirect
measurements (POVMs). Though the generalization is straightforward, it is
important to ascertain that the basic relationships between the generalized
quantitites remain the same for the POVMs as for direct measurements.
