Background for Advances in Data Base Theory -- Data Base Design -- On the Properties of Join Dependencies -- Decomposition of Relations: A Comprehensive Approach -- Adequacy of Decompositions of Relational Databases -- A Method for Helping Discover the Dependencies of a Relation -- General Laws: Deduction and Integrity -- On the Integrity of Typed First Order Data Bases -- Equations Compared with Clauses for Specification of Abstract Data Types -- Optimization in Deductive and Conventional Relational Database Systems -- On Evaluation of Queries Containing Derived Relations in a Relational Data Base -- Reasoning with Data in a Deductively Augmented Data Management System -- Informative Capabilities for Users -- A Formal Approach to Null Values in Database Relations -- About Natural Logic -- Assigning Meaning to Ill-Defined Queries Expressed in Predicate Calculus Language -- On the Feasibility of Informative Answers -- Name Index -- List of Referees -- Addresses of Contributing Authors.