Semantic integrity constraints are business-specific rules that limit the permissible values in a database. For example, a university rule dictating that an "incomplete" grade cannot be changed to an A constrains the possible states of the database. To maintain database integrity, business rules should be identified in the course of database…

Presents the design and implementation of a deductive object-oriented database which is built upon a formally defined data model that uses two languages: an imperative programming language called ROCK (Rule Object Computation Kernel), and a logic language called ROLL (Rule Object Logic Language). (LRW)

Important characteristics of lexical databases and their applications in information retrieval and natural language processing are explained. An ongoing project using various machine-readable sources to build a lexical database is described, and detailed designs of individual entries with examples are included. (Contains 66 references.) (EAM)