“…Assume we are given a canonical factorization of A(z −1 ), it is a natural question to figure out if also A(z −1 ) admits a canonical factorization, and if it is related to the one of A(z −1 ). This issue is motivated by applications in the solution of the Poisson problem in stochastic models, where both the canonical factorizations of A(z) and A(z −1 ) are needed for the existence of the solution and for providing its explicit expression [1].…”