2013/03/01 by Attila Egri-Nagy, Egri-Nagy, Attila, Chrystopher L. Nehaniv +1 · 1 citation
Computer Science · Mathematics · #20B40 #Coding theory and cryptography #F.1.1 #F.4.3 #FOS: Mathematics #Finite Group Theory Research #Group Theory (math.GR) #semigroups and automata theory
paper · pdf · doi:10.48550/arxiv.1303.0091
openalex publication_date 2013/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Motivated by computational efficiency in algebraic automata theory here we define the cascade product of permutation groups as an external product, as a generic extension. It is the most general hierarchical product that uses arbitrary total functions to combine a linearly ordered set of permutation groups. Algebraically speaking, cascade products are explicitly constructed substructures of the iterated wreath product. We show how direct, semidirect and wreath products can be described as cascade products and we also discuss examples of composite groups that can only be constructed exactly as generic extensions by cascade products. The cascade construction naturally generalizes to the transformation semigroup case by leaving out the details of defining inverse operations.