Table of Contents

Universal terms for pseudo-complemented distributive lattices and Heyting algebras.- Clones of operations on relations.- Separation conditions on convexity lattices.- Some independence results in the co-ordinization of arguesian lattices.- Unary operations on completely distributive complete lattices.- Connected components of the covering relation in free lattices.- Varieties with linear subalgebra geometries.- Generalized commutativity.- The word and isomorphism problems in universal algebra.- Linear lattice proof theory: An overview.- Interpolation antichains in lattices.- Subdirectly irreducible and simple boolean algebras with endomorphisms.- A note on varieties of graph algebras.- How to construct finite algebras which are not finitely based.- Finite integral relation algebras.- Some varieties of semidistributive lattices.- Homomorphisms of partial and of complete steiner triple systems and quasigroups.- Principal congruence formulas in arithmetical varieties.- From affine to projective geometry via convexity.- More conditions equivalent to congruence modularity.