RuleOMSA Rule-Based Online Management System
Mohammad Badiul Islam and Guido Governatori
10 October 2015
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 1/14
Research Question
How to take decisions based on data and norms
1 data is retrieved from (relational) database
2 reasoning with norms
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 2/14
Research Question
How to take decisions based on data and norms
1 data is retrieved from (relational) database
2 reasoning with norms
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 2/14
Reasoning with Norms
Contract fragment
3.1 A “Premium Customer” is a customer who has spent more that $10000 in goods.
3.2 Services marked as “special order” are subject to a 5% surcharge. Premium customersare exempt from special order surcharge.
5.2 The (Supplier) shall on receipt of a purchase order for (Services) make them availablewithin one day.
5.3 If for any reason the conditions stated in 4.1 or 4.2 are not met the (Purchaser) is entitledto charge the (Supplier) the rate of $100 for each hour the (Service) is not delivered.
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 3/14
Requirements for Reasoning with Norms
• modelling deontic concepts• Obligations• Prohibitions• Permissions• Violations
• modelling exceptions
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 4/14
Querying Relational Databases
SQL
• set-theory
• first-order logic
• datalog
first-order logic not appropriate to model norms (Herrestad, ICAIL1991)
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 5/14
Querying Relational Databases
SQL
• set-theory
• first-order logic
• datalog
first-order logic not appropriate to model norms (Herrestad, ICAIL1991)
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 5/14
Once upon a time in a landfar far away . . .
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 6/14
Why Defeasible Deontic Logic
Rule-based non-monotonic formalism
• Flexible
• Efficient (linear complexity)
• Directly skeptic semantics
• Argumentation semantics
• Constructive proof theory
• Encompasses other formalisms used in AI and Law
• Applied in several fields/optimised implementations
• Extensible
• Efficient implementations (SPINdle)
• Not affected by Deontic Logic Paradoxes
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 7/14
Defeasible Deontic Logic Blueprint
Combination of an efficient non-monotonic logic (defeasible logic) and a deontic logic ofviolation.
• Facts are indisputable statements.
• Defeasible rules are rules that can be defeated by contrary evidence.
a1, . . . , an ⇒ c
• The superiority relation is a binary relation defined over the set of rules. The superiorityrelation determines the relative strength of two (conflicting) rules.
Extended with deontic operators O, P, F ,⊗, obligation, permission, prohibition, violation(binary)
a1, . . . , an ⇒ Ob1 ⊗ · · · ⊗ Obm
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 8/14
Reasoning with Defeasible Logic
1 A is a fact; or2 there is an applicable rule for A, and either
1 all the rules for ¬A are discarded (i.e., not applicable) or2 every applicable rule for ¬A is weaker than an applicable rule for A.
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 9/14
RuleOMS Idea
• Facts: SQL queries from Databases
• Rules: Defeasible from Norms
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 10/14
RuleOMS Architecture
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 11/14
From SQL to Facts
{"predicate":"beingChild","SQL":"SELECT * FROM tblchildren WHERE
tblchildren.child_crn = $id ANDtblchildren.child_dob >= ${today - 15y}"}
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 12/14
Conclusions
• Developed as part of Child At Risk project
• Modelled NSW Mandatory Reporter Guidelines
• Working on performance evaluation
• Planned to be released as open source soon
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 13/14
Questions?
RuleOMS Copyright NICTA 2015 Mohammad Badiul Islam and Guido Governatori 14/14