An analogue of implicit mapping theorem to formal grammars

In the paper, some approaches to solving the systems of non-commutative polynomial equations in the form of formal power series (FPS) are developed. The approaches are based on the relation of such equations with the corresponding commutative equations. Every FPS is mapped to its commutative image – power series, which is obtained under the assumption that the symbols in it denote commutative variables with the values in the field of complex numbers. The consistency of the system of non-commutative polynomial equations, which is not directly connected with the consistency of its commutative image, is investigated. However, the analogue of the implicit mapping theorem to formal grammars (non-commutative systems) is obtained, namely if the condition of the implicit mapping theorem holds for the commutative image of the system, then not only this, but the initial non-commutative system of equations has a unique solution in the form of FPS.