Paul C. Bell

collaborators

6 papers

cs.FL2026

Irreducibility of Endomorphisms of Finitely Generated Free Semigroups

Paul C. Bell, Eva Foster, Daniel Reidenbach

We introduce and investigate the irreducibility of endomorphisms of finitely generated free semigroups, i.e., we investigate when an endomorphism $ϕ : Σ^{+} - > Σ^{+}$ , where $Σ$ is any…

cs.DM2026

Factorisability of Low Dimensional Non-Negative Integer Matrices

Paul C. Bell, Eva Foster, Daniel Reidenbach +1

We consider the problem of determining if a given two-dimensional nonnegative integer matrix $M$ is the product of two such matrices, excluding trivial units. A matrix $M$ with no…

cs.FL2026

On Word Representations and Embeddings in Complex Matrices

Paul C. Bell, George Kenison, Reino Niskanen +2

Embeddings of word structures into matrix semigroups provide a natural bridge between combinatorics on words and linear algebra. However, low-dimensional matrix semigroups impose s…

cs.FL2026

Irreducibility of Endomorphisms of Finitely Generated Free Semigroups

Paul C. Bell, Eva Foster, Daniel Reidenbach

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…

math.CO2025

The insertion encoding of restricted growth functions

Christian Bean, Paul C. Bell, Abigail Ollson

We adapt the vertical and horizontal insertion encodings of Cayley permutations to enumerate restricted growth functions, which are in bijection with unordered set partitions. For…

math.CO2025

The insertion encoding of Cayley permutations

Christian Bean, Paul C. Bell, Abigail Ollson

We introduce the vertical and horizontal insertion encodings for Cayley permutations which naturally generalise the insertion encoding for permutations. In both cases, we fully cla…