 Examples for "D"-modules include the Weyl algebra itself (acting on itself by left multiplication), the (commutative) polynomial ring "K"["x"1, ..., "x""n"], where "x""i" acts by multiplication and ∂"j" acts by partial differentiation with respect to "x""j" and, in a similar vein, the ring formula_1 of holomorphic functions on C"n" (functions of "n" complex variables.