By the development of new fields and applications, such as Automated Theorem Proving and Logic Programming, Logic has obtained a new and important role in Computer Science. The traditional mathematical way of dealing with Logic is in some respect not tailored for Computer Science - plications. This book emphasizes such Computer Science aspects in Logic. It arose from a series of lectures in 1986 and 1987 on Computer Science Logic at the EWH University in Koblenz, Germany. The goal of this l- ture series was to give the undergraduate student an early and theoretically well-founded access to modern applications of Logic in Computer Science. A minimal mathematical basis is required, such as an understanding of the notation and knowledge about the basic mathematical proof techniques induction). More sophisticated mathematical kno- edge not a precondition read this book. Acquaintance with some conventional programming language, PASCAL, assumed. Several people helped in various ways in the preparation process of the original German version of this book: Johannes KSbler, Eveline and Rainer Schuler, and Hermann Engesser from B.I. Wissenschaftsverlag. Regarding the English version, I want to express my deep gratitude to Prof. Ronald Book. Without him, this translated version of the book would not have been possible.