This monograph is on interpolation and definability, a notion central in pure logic and with significant meaning and applicability in all areas where logic is applied, especially computer science, artificial intelligence, logic programming, philosophy of science and natural language.

1. Introduction and Discussion ; 2. Modal and Superintuitionistic Logics: Basic Concepts ; 3. Superintuitionistic Logics and Normal Extensions of the Modal Logics S4 ; 4. The Interpolation Theorem in Intuitionistic Predicate Calculus ; 5. Interpolation and Definability in Quantified Logics ; 6. Craig's Theorem in Superintuitionistic Logics and Amalgamable Varieties of Pseudoboolean Algebras ; 7. Interpolation, Definability, Amalgamation ; 8. Interpolation in Normal Extensions of the Modal Logic S4 ; 9. Complexity of Some Problems in Modal and Intuitionistic Calculi ; 10. Interpolation in Modal Infinite Slice Logics Containing the Logic K4 ; 11. An Analog of Beth's Theorem in Normal Extensions of the Modal Logic K4 ; 12. Extensions of the Provability Logic ; 13. Syntactic Proof of Interpolation for the Intuitionistic Predicate Logic ; 14. Interpolation by Translation ; 15. Interpolation in (Intuitionistic) Logic Programming ; 16. Interpolation in Goal-directed Proof Systems ; 17. Further Results and Discussion ; Appendix ; References ; Index