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…

Reports on the development of a prototype computerized abstractor's assistant called TEXNET, a text network management system. Features of the system discussed include semantic dependency links; displays of text structure; basic text editing; extracting; weighting methods; and listings of frequent words. (Contains 25 references.) (LRW)

Analyzes attributes of symbols and identifies the need for a suitable management system for retrieving images from a database. A classification structure that incorporates graphic, semantic, and bibliographic dimensions is described; experiments with describing, sorting, and drawing symbols are reviewed; and future work on a database management…