Semisimple A-semigroups and semirings
Semisimplicity of the algebra associated to a biprefix code.
Separative P.I. semigroups are embeddable into a semilattice of groups.
Sets of lengths do not characterize numerical monoids.
Sets with two associative operations
In this paper we consider duplexes, which are sets with two associative binary operations. Dimonoids in the sense of Loday are examples of duplexes. The set of all permutations carries a structure of a duplex. Our main result asserts that it is a free duplex with an explicitly described set of generators. The proof uses a construction of the free duplex with one generator by planary trees.
Simple paramedial groupoids
Simple zeropotent paramedial groupoids are balanced
This short note is a continuation of and and its purpose is to show that every simple zeropotent paramedial groupoid containing at least three elements is strongly balanced in the sense of .
Simplicity for a class of convolution algebras.
Simplicity of wreath product of semigroups with fixed passive semigroup.
Simultaneous representations by metric spaces
Simultaneous representations in discrete structures
Skew semigroup rings.
Skew-monoidal structures on simple rings with several objects.
Small idempotent clones. I
G. Grätzer and A. Kisielewicz devoted one section of their survey paper concerning -sequences and free spectra of algebras to the topic “Small idempotent clones” (see Section 6 of [18]). Many authors, e.g., [8], [14, 15], [22], [25] and [29, 30] were interested in -sequences of idempotent algebras with small rates of growth. In this paper we continue this topic and characterize all idempotent groupoids with (see Section 7). Such groupoids appear in many papers see, e.g. [1], [4], [21], [26,...
Smallest A-ideals in semigroups.
Solid codes and disjunctive domains.
Solid varieties of semigroups.
Solvability and the permutation property in inverse semigroups.
Solvability in inverse semigroups.
Solvable word problems in semigroups.