We give an overview of publications on partial actions and related concepts, paying main
attention to some recent developments on diverse aspects of the theory, such as partial …

The aim of this paper is to study DRC-semigroups by “categorial approach” and give an
Ehresmann–Schein–Nambooripad type theorem (ESN type theorem for short) for this class …

Let α={α g: R g− 1→ R g} g∈ mor (G) be a partial action of a groupoid G on a (not
necessarily associative) ring R and let S= R⋆ α G be the associated partial skew groupoid …

We initiate the study of expansions of monoids in the class of two-sided restriction monoids
and show that generalizations of the Birget–Rhodes prefix group expansion, despite the …

Lawson has obtained an Ehresmann–Schein–Nambooripad theorem (ESN theorem for
short) for Ehresmann semigroups which states that the category of Ehresmann semigroups …

Ehresmann monoids form a variety of bi-unary monoids, that is, monoids equipped with two
basic unary operations, the images of which coincide and form a semilattice of projections …

oup_qmathj_hay062 1..30 ++ Page 1 PARTIAL GALOIS COHOMOLOGY AND RELATED
HOMOMORPHISMS by M. DOKUCHAEV † (Instituto de Matemática e Estatística, Universidade …

Given a group G and a partial factor set σ of G, we introduce the twisted partial group
algebra κ par σ G, which governs the partial projective σ-representations of G into algebras …

As generalizations of inverse semigroups, restriction semigroups and regular*∗-semigroups
are investigated by many authors extensively in the literature. In particular, Lawson and …

We call a restriction semigroup almost perfect if it is proper and the least congruence that
identifies all its projections is perfect. We show that any such semigroup is isomorphic to a …