What is a Logical System? by D. M. Gabbay (Professor of Computing Science, Department of Computing, Professor of Computing Science, Department of Computing, Imperial College of Science, Technology and Medicine, University of London)
This extraordinary collection of papers addresses a fundamental question of logic and computation. What is a logical system?. With contributions from many world famous researchers, it presents a wide spectrum of views on the problem, reflecting mainstream current approaches to logic and how it is applied.