Structural proof theory is a branch of logic that studies the general structure and properties of logical and mathematical proofs. This book is both a concise introduction to the central results and methods of structural proof theory, and a work of research that will be of interest to specialists. The book is designed to be used by students of philosophy, mathematics, and computer science. A special feature of the volume is a computerized system for developing proofs interactively, downloadable from the web and regularly updated.

• General introduction for students in philosophy, mathematics, and computer science • Downloadable computer program (regularly updated by authors) for developing proofs interactively • Von Plato a successful and well-known author

Contents Introduction; 1. From natural deduction to sequent calculus; 2. Sequent calculus for institutionistic logic; 3. Sequent calculus for classical logic; 4. The quantifiers; 5. Variants of sequent calculi; 6. Structural proof analysis of axiomatic theories; 7. Intermediate logical systems; 8. Back to natural deduction; Conclusion: diversity and unity in structural proof theory; Appendix A. Simple type theory and categorical grammar; Appendix B. Proof theory and constructive type theory; Appendix C. A proof editor for sequent calculus.