A Galois correspondence for universal algebras
A Galois theory with stable units for simplicial sets.
A general existence theorem on partial algebras and its special cases
A generalization of a theorem of Skala
A generalization of equivalence relations.
A generalization of Płonka sums
A generalization of the direct product of universal algebras
A groupoid characterization of Boolean algebras
We present a groupoid which can be converted into a Boolean algebra with respect to term operations. Also conversely, every Boolean algebra can be reached in this way.
A lattice of homomorphs
A matrix characterization of the maximal groups in
A multiplication of -varieties of orthodox semigroups
We define semantically a partial multiplication on the lattice of all e–varieties of regular semigroups. In the case that the first factor is an e–variety of orthodox semigroups we describe our multiplication syntactically in terms of biinvariant congruences.
A multiplication of e-varieties of regular -solid semigroups by inverse semigroup varieties
A multiplication of e-varieties of regular -solid semigroups by inverse semigroup varieties is described both semantically and syntactically. The associativity of the multiplication is also proved.
A new example of a limit variety.
A new Proof of Prešić's Theorem on Finite Equations
A new proof of Reiterman's theorem
A New Proof of the Eilenberg-Zilber-Cartier Theorem.
A non-commutative free algebra of rank 0
A normal form for restricted exponential functions
A note on algebraic categories
A note on categories of partial algebras