This volume presents the papers selected for the SymposiumLogic at Tver '92, held at Sokol, near Tver, Russia in July1992. It is the second in a series of international symposiaon logical foundations of computer science held in Russia. The meeting is a joint effort of scholars from both theformer Soviet Union and the West, and indicates a new era ofinternational cooperation. Sponsors of the meeting include:the Association for Computing Machinery, the Association forSymbolic Logic, andthe Committee on MathematicalFoundations of Computer Science of IEEE. The book is a unique source of information on the state ofcomputer science research in the former Soviet Union andpresents important discoveries in the area of logicalfoundations of computer science.