Via an encoding of the Modified Post’s Correspondence Problem, this paper shows that it is undecidable whether an automatic semigroup is cancellative.

For certain a, b ∈ N, the Arithmetic Congruence Monoid M(a, b) is a multiplicatively closed subset of N given by {x ∈ N : x ≡ a (mod b)}∪{1}. An irreducible in this monoid is any element that cannot be factored into two elements, each greater than 1. Each monoid element (apart from 1) may be factored into irreducibles in at least one way. The elasticity of a monoid element (apart from 1) is the...

The dual symmetric inverse monoid I ∗ n is the inverse monoid of all isomorphisms between quotients of an n-set. We give a monoid presentation of I ∗ n and, along the way, establish criteria for a monoid to be inverse when it is generated by completely regular elements.

We consider certain decision problems for the free model of theory Cartesian monoids. introduce a computation based on notion single stack one-way PDA due to Ginsburg, Greibach and Harrison. This allows us solve such as (1) Given finite set B elements an element F, is F product members B? (2) Is submonoid generated by infinite? fragments monoid. These include right invertible so our results app...

We exhibit faithful representations of the hypoplactic, stalactic, taiga, sylvester, Baxter and right patience sorting monoids each finite rank as upper triangular matrices over any semiring from a large class including tropical fields characteristic 0. By analysing image these representations, we show that variety generated by single hypoplactic (respectively, stalactic or taiga) monoid at lea...

The aim of this paper is to review thoroughly the applications ∩ -large pseudo N-injective acts in quasi-Frobenius monoid theory, and therefore, relationship with some class injectivity studied. Applications properties injective theory are proven. Also, it’s proved that subsequent parity, every union (direct sum) two a act if only under Noetherian condition for right S. Additionally, we categor...

Let M(A, θ) be a free partially commutative monoid. We give here a necessary and sufficient condition on a subalphabet B ⊂ A such that the right factor of a bisection M(A, θ) = M(B, θB).T be also partially commutative free. This extends strictly the (classical) elimination theory on partial commutations and allows to construct new factorizations of M(A, θ) and associated bases of LK(A, θ).

We introduce two partially overlapping classes of pathwise dualities between interacting particle systems that are based on commutative monoids (semigroups with a neutral element) and semirings, respectively. For whose local state space has elements, this approach yields unified treatment the well-known additive cancellative dualities. spaces three or more we discover several new

We introduce and study the partial singular braid monoid PSBn, a monoid that contains both the inverse braid monoid IBn and the singular braid monoid SBn. Our main results include a characterization of Green’s relations, a presentation in terms of generators and relations, and a proof that PSBn embeds in the semigroup algebra C[IBn].