There is a large amount of literature on the topic of covarieties, coequations and
coequational specifications, dating back to the early seventies. Nevertheless, coequations …

Guarded Kleene Algebra with Tests (GKAT) is an efficient fragment of KAT, as it allows for
almost linear decidability of equivalence. In this paper, we study the (co) algebraic …

Recently, two apparently quite different duality-based approaches to automata minimisation
have appeared. One is based on ideas that originated from the controllability-observability …

Eilenberg's variety theorem marked a milestone in the algebraic theory of regular languages
by establishing a formal correspondence between properties of regular languages and …

Eilenberg's variety theorem marked a milestone in the algebraic theory of regular languages
by establishing a formal correspondence between properties of regular languages and …

We establish an Eilenberg-type correspondence for data languages, ie languages over an
infinite alphabet. More precisely, we prove that there is a bijective correspondence between …

Categorical dualities are an important tool in the study of (modal) logics. They offer
conceptual understanding and enable the transfer of results between the different semantics …

This extended abstract first presents a new category theoretic approach to equationally
axiomatizable classes of algebras. This approach is well-suited for the treatment of algebras …

The aim of the paper is to build a connection between two approaches towards categorical
language theory: the coalgebraic and algebraic language theory for monads. For a pair of …