A. Citkin studies for many years the theory of the Yankov characteristic formulas, their generalizations and applications in different areas of propositional, modal and algebraic logic.I. Vandoulakis is Adjunct Professor in history and philosophy of science at the Hellenic Open University, Greece. He holds a Ph.D. in history of mathematics from Moscow M.V. Lomonosov State University (1991). He has published on history and philosophy of Greek mathematics, history of mathematical logic, philosophy and the foundations of mathematics.

• Chapter 1. Short autobiography (Vadim A. Yankov), Part I: Non-classical logics.- Chapter 2. V. Yankov’s contributions to propositional Logic (Alex Citkin).- Chapter 3. Dialogues and proofs; Yankov’s contribution to proof theory (Andrzej Indrzejczak).- Chapter 4. Jankov formulas and axiomatization techniques for intermediate logics (Guram Bezhanishvili, Nick Bezhanishvili).- Chapter 5. Yankov Characteristic formulas (an algebraic account) (Alex Citkin).- Chapter 6. The invariance modality (Silvio Ghilardi).- Chapter 7. The Lattice NExtS41 as composed of replicas of NExtInt, and beyond (Alexei Muravitsky).- Chapter 8. An Application of the Yankov characteristic formulas (Valery Plisko).- Chapter 9. A note on disjunction and existence properties in predicate extensions of intuitionistic logic – An application of Jankov formulas to predicate logics (Nobu-Yuki Suzuki).- Part II: History and philosophy of mathematics.- Chapter 10. On V.A. Yankov’s contribution to the history of foundations of mathematics (Ioannis M. Vandoulakis).- Chapter 11. On V.A. Yankov’s existential interpretation of the early Greek philosophy. The case of Heraclitus (Tatiana Yu. Denisova).- Chapter 12. On V.A. Yankov’s hypothesis of the rise of Greek mathematics (Ioannis M. Vandoulakis).

A. Citkin studies for many years the theory of the Yankov characteristic formulas, their generalizations and applications in different areas of propositional, modal and algebraic logic.I. Vandoulakis is Adjunct Professor in history and philosophy of science at the Hellenic Open University, Greece. He holds a Ph.D. in history of mathematics from Moscow M.V. Lomonosov State University (1991). He has published on history and philosophy of Greek mathematics, history of mathematical logic, philosophy and the foundations of mathematics.

• Chapter 1. Short autobiography (Vadim A. Yankov), Part I: Non-classical logics.- Chapter 2. V. Yankov’s contributions to propositional Logic (Alex Citkin).- Chapter 3. Dialogues and proofs; Yankov’s contribution to proof theory (Andrzej Indrzejczak).- Chapter 4. Jankov formulas and axiomatization techniques for intermediate logics (Guram Bezhanishvili, Nick Bezhanishvili).- Chapter 5. Yankov Characteristic formulas (an algebraic account) (Alex Citkin).- Chapter 6. The invariance modality (Silvio Ghilardi).- Chapter 7. The Lattice NExtS41 as composed of replicas of NExtInt, and beyond (Alexei Muravitsky).- Chapter 8. An Application of the Yankov characteristic formulas (Valery Plisko).- Chapter 9. A note on disjunction and existence properties in predicate extensions of intuitionistic logic – An application of Jankov formulas to predicate logics (Nobu-Yuki Suzuki).- Part II: History and philosophy of mathematics.- Chapter 10. On V.A. Yankov’s contribution to the history of foundations of mathematics (Ioannis M. Vandoulakis).- Chapter 11. On V.A. Yankov’s existential interpretation of the early Greek philosophy. The case of Heraclitus (Tatiana Yu. Denisova).- Chapter 12. On V.A. Yankov’s hypothesis of the rise of Greek mathematics (Ioannis M. Vandoulakis).

A. Citkin studies for many years the theory of the Yankov characteristic formulas, their generalizations and applications in different areas of propositional, modal and algebraic logic.I. Vandoulakis is Adjunct Professor in history and philosophy of science at the Hellenic Open University, Greece. He holds a Ph.D. in history of mathematics from Moscow M.V. Lomonosov State University (1991). He has published on history and philosophy of Greek mathematics, history of mathematical logic, philosophy and the foundations of mathematics.

• Chapter 1. Short autobiography (Vadim A. Yankov), Part I: Non-classical logics.- Chapter 2. V. Yankov’s contributions to propositional Logic (Alex Citkin).- Chapter 3. Dialogues and proofs; Yankov’s contribution to proof theory (Andrzej Indrzejczak).- Chapter 4. Jankov formulas and axiomatization techniques for intermediate logics (Guram Bezhanishvili, Nick Bezhanishvili).- Chapter 5. Yankov Characteristic formulas (an algebraic account) (Alex Citkin).- Chapter 6. The invariance modality (Silvio Ghilardi).- Chapter 7. The Lattice NExtS41 as composed of replicas of NExtInt, and beyond (Alexei Muravitsky).- Chapter 8. An Application of the Yankov characteristic formulas (Valery Plisko).- Chapter 9. A note on disjunction and existence properties in predicate extensions of intuitionistic logic – An application of Jankov formulas to predicate logics (Nobu-Yuki Suzuki).- Part II: History and philosophy of mathematics.- Chapter 10. On V.A. Yankov’s contribution to the history of foundations of mathematics (Ioannis M. Vandoulakis).- Chapter 11. On V.A. Yankov’s existential interpretation of the early Greek philosophy. The case of Heraclitus (Tatiana Yu. Denisova).- Chapter 12. On V.A. Yankov’s hypothesis of the rise of Greek mathematics (Ioannis M. Vandoulakis).