Daniel Reidenbach

Irreducibility of Endomorphisms of Finitely Generated Free Semigroups

We introduce and investigate the irreducibility of endomorphisms of finitely generated free semigroups, i.e., we investigate when an endomorphism $φ: Σ^+ \to Σ^+$, where $Σ$ is any alphabet, can be nontrivially expressed as a composition $φ= ψ_2 \circ ψ_1$ of endomorphisms $ψ_1,...