Lengths of words in transformation semigroups generated by digraphs

P. J. Cameron, A. Castillo-Ramirez, M. Gadouleau +1

Given a simple digraph $D$ on $n$ vertices (with $n\ge 2$), there is a natural construction of a semigroup $⟨D⟩$ associated with $D$. For any edge $(a,b)$ of $D$, let $…