theorem of Ritt

The Ritt theorem concerns the composition of complex polynomials. It states that if a polynomial can be written as a composition of simpler polynomials in multiple ways, these different decompositions are essentially related by certain transformations. Specifically, all decompositions are connected through a finite sequence of basic operations, such as swapping factors or applying linear changes. This result helps mathematicians understand the fundamental structure of polynomial functions, ensuring that, despite apparent differences, their compositions are related by well-understood modifications, leading to a clearer classification of polynomial decompositions.