This volume contains the proceedings of two Russian conferences on logic programming, held in 1990 in Irkutsk and in 1991 in St. Petersburg. The aim of the conferences was to bring together researchers from the Russian and the international logic programming communities. Topics covered in the volume include: logic programming, automated theorem proving, non-monotonic reasoning, applications of mathematical logic to computer science, deductive databases, implementation of declarative concepts, and programming in non-classical logics. This is the first volume to represent activity in the field of logic programming in the countries of the former Soviet Union.