COMPLEXITY OF NON-MONOTONIC LOGICS

The study of the complexity of logical problems has provided a very fruitful field of research since many decades. On the one hand researchers have tried to classify exactly in terms of complexity classes and upper and lower bounds the complexity of decision and other logical problems. Although in general such problems are of high complexity, efforts have been made to develop efficient algorithms to solve such problems when restricted to important logic fragments, that are relevant in the praxis. Michael Thomas and Heribert Vollmer survey in this excellent column recent complexity results for fragments of languages of non-monotonic logics.