© 2005, XSB, Inc, Stony Brook, NY XcelLog: A User-Centered Deductive Spreadsheet System David S. Warren, I.V. Ramakrishnan, C.R. Ramakrishnan, Tatyana Vidrevich, Chris Rued, Harpreet Singh

© 2005, XSB, Inc, Stony Brook, NY

Conventional Spreadsheets 2-dimensional presentation User interacts with table cells To specify a function: –Each cell contains a unique value –Basic specification is that the content of a cell is a function of the contents of other cells Copy-paste gestures support powerful abstraction-concretion operations

© 2005, XSB, Inc, Stony Brook, NY Deductive Spreadsheets Extend to allow a cell to contain a set of values. –Add union operator (and other set operators). –Lift all functional operators to apply point-wise over sets. –Use semantically meaningful row and column identifiers –Permit recursive definitions (stratified), and use least fixed point (perfect model) semantics. Extend copy-paste gestures to handle sets.

© 2005, XSB, Inc, Stony Brook, NY For Exploring Rule Bases Rule systems are everywhere –Business rules –Configuration specification –Authorization –Security policy configuration –Vulnerability analysis Goal is to allow rule-system users to build and experiment with their systems themselves, without a programmer as intermediary

© 2005, XSB, Inc, Stony Brook, NY DSS Prototype Implementation As Add-In to Microsoft Excel® Add-In programmed in XSB logic programming system –Depends fundamentally on XSB’s tabling Excel® XSB sheet_changed =DSS paste etc. getFormulaAt setFormulaAt getValueAt etc. ops

© 2005, XSB, Inc, Stony Brook, NY DEMOS Transitive closure from scratch (including basic ideas) Supply Chain Ultralog-Military logistics management Shortest Path

SD-1-AD: Maintenance & Repair Scenario 1-AD 1-BDE- 1-AD DISCOM- 1-AD 16-CSG (1-AD) 123- MSB ARBN INFBN 501- FSB 485- CSB 18- MAINTBN 592- ORDCO 227- SUPPLYCO NCA USAEUR USEUCOM 5-CORPS 7-CSG (5-CORPS) 71- MAINTBN 565- RPRPTCO 3-SUPCOM -HQ DLAHQOSCTRANSCOM 21-TSC -HQ 29- SPTGP 51- MAINTBN 191- ORDBN 343- SUPPLYCO 37- TRANSGP 6- TCBN 110-POL- SUPPLYCO HNS AWR POL- SUPPLYCO 106- TCBN 28- TCBN 3-BDE- 1-AD ARBN INFBN 125- FSB GRAINGER NEWARK DLA- AVN DLA- OTHER CCAD AVNBDE- 1-AD 1-1- CAVSQDN AVNBN AVNBN 127- DASB Task Types Supply SupportCommand Assignment Maintenance Supply Repair Parts THEATER CORPS DIV BDE Maintain COMM- ERCIAL DRY-TECH PARTS- ALA-CARTE WARNER- ROBBINS PWC-SAN -DIEGO Supply Repair Parts Supply Repair Parts Agent Activities Request Maintenance Perform Maintenance, Request Parts, Manage Inventory ARMY JOINT ECHELON

© 2005, XSB, Inc, Stony Brook, NY What Deductive Spreadsheets Add to Spreadsheets Ability to define rules over sets naturally Ability to deal with recursion (XSB): –Hierarchies and cyclic structures –Dynamic programming All within the spreadsheet metaphor

© 2005, XSB, Inc, Stony Brook, NY Issues Set-based Operators –Relational Algebra Types (for Rows and Columns) Abstract/Concrete –Excel has no variables, an advantage –Copy-paste infers a generalization DSS infers exist abstractions Can/Should they be avoided? –Auxiliary tables provide scoping…

© 2005, XSB, Inc, Stony Brook, NY Planned Work Explanations –Integrate into Excel’s framework –Based of previous work on justification Incremental Re-evaluation –Based on work within XSB framework

© 2005, XSB, Inc, Stony Brook, NY Future Work: LOTS Supported by DARPA: SBIR Grant, Phase I, W31P4Q-05-C-R034