Fixed points in free process algebras. II (Q913498)

Iterative equations involving semilinear and nonlinear left simple polynomials are considered. It is given a complete characterization of the fixed points of equations involving A-semilinear polynomials (Th. 4.6). The authors proved that: For \(\delta\)-semilinear polynomials p(x), \(p^ 5(x)=p^ 6(x)\) (Th. 4.12). For some \(\{\) \(\tau\),\(\delta\) \(\}\)-semilinear polynomials p(x), \(p^ 6(x)=p^ 7(x)\) (Th. 5.20). Moreover, for some nonlinear polynomials p(x), sufficient conditions for the solutions to \(x=p(x)\) are given.