This book develops model theory independently of any concrete logical system or structure, within the abstract category-theoretic framework of the so called institution theory . The development includes most of the important methods and concepts of conventional concrete model theory at the abstract institution-independent level. Consequently it is easily applicable to a rather large diverse collection of logics from the mathematical and computer science practice.

This book constitutes the thoroughly refereed post-conference proceedings of the 22nd International Workshop on Algebraic Development Techniques, WADT 2014, held in September 2014 in Sinaia, Romania. The 8 revised papers presented were carefully reviewed and selected from 13 presentations and focus together with one invited paper on foundations of algebraic specification, approaches to formal specification including process calculi and models of concurrent, distributed and mobile computing, specification languages, methods, and environments, semantics of conceptual modeling methods and techniques, model-driven development, graph transformations, term rewriting and proof systems, integration of formal specification techniques, formal testing and quality assurance, validation, and verification.