The logiform system

Abstract Logiform is a programming system that exploits the spreadsheet, relational data base, and logic programming paradigms. Spreadsheets are used to provide views of data base relations, and spreadsheet cells are annotated by constraints expressed in logic programming. The system cooperates with the user to find correct values for the cells; its principal characteristic is its ability to search for solutions incrementally, that is, by providing, at each computation step, new cell values and a refined set of constraints.