In a formal way, analytic dynamical systems can be solved by the Peano-Baker formula (whose convergence behavior outside a small neighborhood of the starting point is almost impossible to control). In a canonical way, the operators of the Peano-Baker series can be mapped onto the elements of a ring of power series of noncommuting elements. A theorem of Fliess [1] characterizes those power series that represent Peano-Baker series. For the degenerate case of a polynomial, the author gives a MACSYMA program that produces the differential operators of the dynamical system. A reader interested in the field will find the paper contains a generally careful introduction (despite a misprint in Definition 2.1 and an error in Example 2.2) and a good bibliography.