For a canonical unbounded CP-map Lambda(.) from the vector space of densely
defined closed operators on a Hilbert space H, into the vector space of de
nsely defined closed operators on the symmetric Fock space over H, we prove
that Lambda(A) is directly Lambda(B)-relatively bounded provided A and B a
re positive and A is directly B-relatively bounded, that is, \\A Psi\\ less
than or equal to c\\B psi\\ on dom(B).
We consider formal generators on the symmetric Fock space corresponding to
this map Lambda(.) and show that they determine uniquely certain quantum dy
namical semigroups.