Intellisheet: a spreadsheet system expanded by including constraint

This paper describes our research into the expansion of the spreadsheet paradigm by the incorporation of solvers for systems of linear and finite-domain constraints. An extended spreadsheet system, called Intellisheet, allows the entry of expressions that represent linear and finite-domain constraints, along with arithmetic expressions, in individual cells. The systems of constraints that have been entered are automatically solved by constraint solvers and the resulting solutions are displayed in the cells that contain the expressions or in other assigned cells. Intellisheet's GUI also has some special features to facilitate constraint programming. Incorporating constraint solvers extends the scope of the spreadsheet paradigm to declarative programming and provides an easier way to solve a broad class of problems, including linear optimization and discrete problems.