Formal Methods and the Theory of Social Choice -- Relations Making Their Way from Logics to Mathematics and Applied Sciences -- Boolean Logics with Relations -- Relation Algebra and RelView in Practical Use: Construction of Special University Timetables -- A Relation Algebraic Semantics for a Lazy Functional Logic Language -- Latest News about Demonic Algebra with Domain -- On the Structure of Demonic Refinement Algebras with Enabledness and Termination -- Multi-objective Problems in Terms of Relational Algebra -- The Lattice of Contact Relations on a Boolean Algebra -- A Non-probabilistic Relational Model of Probabilistic Kleene Algebras -- Increasing Bisemigroups and Algebraic Routing -- Lazy Relations -- The Algebraic Approach I: The Algebraization of the Chomsky Hierarchy -- The Algebraic Approach II: Dioids, Quantales and Monads -- Automated Reasoning for Hybrid Systems — Two Case Studies — -- Non-termination in Idempotent Semirings -- Formal Concepts in Dedekind Categories -- The Structure of the One-Generated Free Domain Semiring -- Determinisation of Relational Substitutions in Ordered Categories with Domain -- Boolean Algebras and Stone Maps in Schröder Categories -- Cardinality in Allegories -- Solving Linear Equations in *-continuous Action Lattices -- Reactive Probabilistic Programs and Refinement Algebra -- Knowledge and Games in Modal Semirings -- Theorem Proving Modulo Based on Boolean Equational Procedures -- Rectangles, Fringes, and Inverses -- An Ordered Category of Processes -- Automatic Proof Generation in Kleene Algebra.