  We consider here a new operator, called ``super nabla'', which is shown to be
generic among operators for which the modified Macdonald polynomials are joint
eigenfunctions. All previously known Macdonald eigenoperators can readily be
obtained from super nabla, including the usual nabla operator, the Delta
operators, and other operators that have appeared in the literature. Thus, the
super nabla operator furnishes an overall unified viewpoint on this family of
operators, as well as opening up new possibilities. We prove several new
identities arising from specializations of the parameters $q$ and $t$ involved
in the specification of these operators, as well as unifying combinatorial
interpretations.
