1. From POSL to d-POSL: Making the Positional-Slotted Language Defeasible Advisors: Nick Bassiliades, Efstratios Kontopoulos Instructor: Dr. Harold Boley University of New Brunswick, Fredericton, NB 21 November 2011 1 Team 1Daniel Latimer Hanin Almutairi Chaudhry Usman Ali

2. 2 PROJECT DEVELOPMENT MODEL

3. POSL  POSL integrates positional and slotted knowledge for humans e.g. Prolog’s positional and F-logic’s slotted knowledge. Positional Notation: shipment(PC,47.5,BostonMos,LondonSciM).( Prolog Inspired ) Slotted Notation: shipment(cargo->PC;price->47.5,source->BostonMos;dest- >LondonSciM). ( F-Logic Inspired ) Positional-slotted Notation: shipment(PC,47.5;source->BostonMos;dest->LondonSciM). POSL : -> ^^ URI ->IRI POSL 1.0 Boley, Harold. "Integrating Positional and Slotted Knowledge on the Semantic Web". Journal of Emerging Technologies in Web Intelligence (Nov 2010). 343-353. 3

4. POSL FLOW Changes implemented in original ANTLR2 grammar POSL.g POSL ANTLR POSL 1.0 4 separator between a variable and its type changed from ":" to "^^"

5. Defeasible Logic  “Defeasible logic, originally created by Donald Nute with a particular concern about efficiency and implementation, is a simple and efficient rule based non-monotonic formalism. Over the years the logic has been developed and extended, and several variants have been proposed”.  “The main intuition of the logic is to be able to derive “plausible” conclusions from partial and sometimes conflicting information”. defeasible.org 5

6. Kinds of Rules  There are three kinds of rules in defeasible logic, each represented by a different arrow: Kontopoulos, Efstratios and Bassiliades, Nick and Antoniou, Grigoris: Visualizing Semantic Web proofs of defeasible logic in the DR-DEVICE system (April, 2011) http://dl.acm.org/citation.cfm?id=1942399 6

7. Features of d-POSL Rule Label: This is needed in defeasible logics for expressing the superiority relations among rules. Rule Type: There are three kinds of rules in defeasible logic (previous slide). Negation and Negation-As-Failure (NAF): Both types of negation are needed in defeasible logics. Superiority Relation Given two rules r1 and r2, if r1 > r2, then r1 is considered superior to r2 and r2 is inferior to r1. The superiority relation is used in resolving conflicts among competing rules. Kontopoulos, Efstratios and Bassiliades, Nick and Antoniou, Grigoris: Visualizing Semantic Web proofs of defeasible logic in the DR-DEVICE system (April, 2011) http://dl.acm.org/citation.cfm?id=1942399 7

8. ANTLR  “ANTLR, ANother Tool for Language Recognition, is a language tool that provides a framework for constructing recognizers, interpreters, compilers, and translators from grammatical descriptions containing actions in a variety of target languages”.target languages http://www.antlr.org EBNFGrammar ANTLR Lexer Parser 8

9. How it works Stream of Characters LEXER PARSER Interpretation of tokens according to ANTLR rules Tokens 9

10. Interpretation 10 r1: acceptable(apartment->?x^^ACCOMMODATION) :- carlo:apartment(apt845^carlo:age->12).

11. Test Rig 11

12. OO jDREW modifications  Update the Converter application  Current features:  Convert RuleML 0.88/0.91  to POSL 0.91  Convert POSL 0.91 to  RuleML 0.88 or 0.91 12

13. OO jDREW modifications  Upgraded Functionality  1. Now parses POSL  1.0 instead of 0.91  2. Convert RuleML 0.88/  0.91/1.0 to POSL 1.0  3. Functionality to upgrade  POSL 0.91 to 1.0  4. Convert POSL 1.0 to  RuleML 0.88 or 0.91/1.0 13

14. OO jDREW modifications  Demonstration 14

15. OO jDREW modifications  To accomplish this:  Update the POSL input field  - Generate LEXER and PARSER of modified grammar using ANTLR 2.7.5  Added support for legacy code - POSL 0.91  - Created a “POSL 0.91 to 1.0 button”  Convert RuleML to POSL 1.0 instead of 0.91 15

16. Conclusions  Changes implemented in POSL to 1.0.  Functionality updated in OO jDREW.  Current d-POSL grammar based on EBNF presented in:  Kontopoulos, Efstratios and Bassiliades, Nick and Antoniou, Grigoris: Visualizing Semantic Web proofs of defeasible logic in the DR-DEVICE system (April, 2011) http://dl.acm.org/citation.cfm?id=1942399  A test rig to label input according to specification in the grammar has been implemented.  http://d-posl.wikispaces.com/file/view/demoDpos_fat.jar 16

17. Future Work  Further work can be done in d-POSL to refine the grammar according to new requirements.  d-POSL grammar can be implemented into a stand alone application. 17

18. References  Boley, Harold. "Integrating Positional and Slotted Knowledge on the Semantic Web". Journal of Emerging Technologies in Web Intelligence (Nov 2010). 343-353.  Kontopoulos, Efstratios and Bassiliades, Nick and Antoniou, Grigoris: "Visualizing Semantic Web proofs of defeasible logic in the DR-DEVICE system". Knowledge- Based Systems (April 2011). 406-419.  Parr, Terrence. The Definitive ANTLR Reference: Building Domain-Specific Languages. 2007. 18