Adding Deductive Logic to a COTS Spreadsheet

We will integrate a deductive logic system with the GUI from the most successful Commercial-Off-The-Shelf (COTS) spreadsheet – Excel. We will then deploy this extension as an Excel Add-In. The deductive logic system will be OWL, W3C’s ontology language for the semantic web, extended with OWL’s rule language. This will extend the variety of data that can be displayed in spreadsheet cells to encompass the symbolic (non-numeric, non-textual) classes definable in ontologies. The Excel formula language will be transparently extended to support deduction rules. This will enable logic-derived values to act as input to native Excel formulas and vice versa. We can accomplish this integration because Excel already provides the critical extensibility hooks through its plugin architecture, providing for GUI extensions (new tools, menus), providing callbacks to intervene in crucial user events, such as filling in a cell with a user-entered or derived value, and provide the plugin code with extensive access to an object-oriented model of the spreadsheet itself.