The amalgamation class of a discriminator variety is finitely axiomatizable.- Free spectra of 3-element algebras.- Tree algebras and chains.- Boolean constructions.- Extension of polygroups by polygroups and their representations using color schemes.- A characterization for congruence semi-distributivity.- Geometrical applications in modular lattices.- Subdirectly irreducible algebras in modular varieties.- A survey of varieties of lattice ordered groups.- On join-indecomposable equational theories.- Idealfree CIM-groupoids and open convex sets.- Finite forbidden lattices.- Inherently nonfinitely based finite algebras.- Tensor products of Boolean algebras.- G-principal series of stocks in an algebra.- Algebras of functions from partially ordered sets into distributive lattices.- Galois theory for partial algebras.- Every finite algebra with congruence lattice M 7 has principal congruences.- Nilpotence in permutable varieties.