Invited Papers -- Topological Representation of Precontact Algebras -- Relational Semantics Through Duality -- Duality Theory for Projective Algebras -- Contributed Papers -- Relational Approach to Boolean Logic Problems -- Static Analysis of Programs Using Omega Algebra with Tests -- Weak Contact Structures -- On Relational Cycles -- A Framework for Kleene Algebra with an Embedded Structure -- Non-termination in Unifying Theories of Programming -- Towards an Algebra of Hybrid Systems -- Relational Correspondences for Lattices with Operators -- Control-Flow Semantics for Assembly-Level Data-Flow Graphs -- Relational Implementation of Simple Parallel Evolutionary Algorithms -- Lattice-Based Paraconsistent Logic -- Verification of Pushdown Systems Using Omega Algebra with Domain -- wp Is wlp -- Relational Representability for Algebras of Substructural Logics -- Knuth-Bendix Completion as a Data Structure -- Quantifier Elimination in Elementary Set Theory -- Time-Dependent Contact Structures in Goguen Categories.