  The generalized parallel sum of two monotone operators via a linear
continuous mapping is defined as the inverse of the sum of the inverse of one
of the operators and with inverse of the composition of the second one with the
linear continuous mapping. In this article, by assuming that the operators are
maximal monotone of Gossez type (D), we provide sufficient conditions of both
interiority- and closedness-type for guaranteeing that their generalized sum
via a linear continuous mapping is maximal monotone of Gossez type (D), too.
This result will follow as a particular instance of a more general one
concerning the maximal monotonicity of Gossez type (D) of an extended parallel
sum defined for the maximal monotone extensions of the two operators to the
corresponding biduals.
