2CL Protocols: Interaction Patterns Specification in Commitment - - PowerPoint PPT Presentation

2CL Protocols: Interaction Patterns Specification in Commitment Protocols

Elisa Marengo

Universit` a degli Studi di Torino Scuola di Dottorato in Scienze ed Alta Tecnologia Dottorato in Informatica

Ph.D. Thesis Defence - Torino, October 19, 2012

Advisor: Prof. Matteo Baldoni - Prof. Cristina Baroglio Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 1 / 41

Interaction Protocols

Representation of Complex Systems

Current trends: Advent of distributed and heterogeneous systems Moving from monolithic towards component-based approaches Moving from defining the flow of execution towards defining coordination among the components Interaction protocols are means for achieving the desired coordination among the components

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 2 / 41

Interaction Protocols

Representation of Complex Systems

Current trends: Advent of distributed and heterogeneous systems Moving from monolithic towards component-based approaches Moving from defining the flow of execution towards defining coordination among the components Interaction protocols are means for achieving the desired coordination among the components

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 2 / 41

Interaction Protocols

Interaction Protocols

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 3 / 41

Achieve coordination Providing all the necessary tools Accounting for components’ characteristics

Interaction Protocols

Interaction Protocols

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 3 / 41

Achieve coordination Providing all the necessary tools Accounting for components’ characteristics Reuse Improving performances Decreasing costs

Interaction Protocols

Interaction Protocols

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 3 / 41

Achieve coordination Providing all the necessary tools Accounting for components’ characteristics Reuse Improving performances Decreasing costs Applicable to real cases

Interaction Protocols

Interaction Protocols

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 3 / 41

Achieve coordination Providing all the necessary tools Accounting for components’ characteristics Reuse Improving performances Decreasing costs Usable Tools Methodologies Supports Applicable to real cases

Interaction Protocols

Interaction Protocols

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 3 / 41

Achieve coordination Providing all the necessary tools Accounting for components’ characteristics Formal Foundation Reuse Improving performances Decreasing costs Usable Tools Methodologies Supports Applicable to real cases

Interaction Protocols

Interaction Protocol and MASs

A MAS is an abstraction used to simulate complex systems made of interacting parties (agents) where:

the interacting parties are usually conceived as heterogeneous and autonomous; they interact in order to achieve some objectives.

Interaction protocols are means to achieve coordination/cooperation in MASs [Weiss, 1999, Wooldridge, 2002]

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 4 / 41

Interaction Protocols

How to specify an Interaction Protocol?

By specifying the allowed sequences of actions Automata Finite State Machines Petri Nets UML Diagrams (Sequence diagrams) AUML Diagrams (Interaction diagrams) By specifying only mandatory and forbidden requirements Expectation-based approaches Commitment-based approaches

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 5 / 41

Interaction Protocols

How to specify an Interaction Protocol?

By specifying the allowed sequences of actions Automata Finite State Machines Petri Nets UML Diagrams (Sequence diagrams) AUML Diagrams (Interaction diagrams) By specifying only mandatory and forbidden requirements Expectation-based approaches Commitment-based approaches

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 5 / 41

Interaction Protocols Commitment Protocols

Commitment Protocols

C(x, y, p, q) In Commitment protocols [Yolum and Singh, 2002] By performing some actions the agents socially commit to do (or achieve) something The expectation is that at the end all commitments are satisfied Characteristics they respect the agents’ autonomy they allow agents for flexible behaviours (what rather than how) they are verifiable However, Commitment Protocols do not account for Patterns of Interaction

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 6 / 41

Interaction Protocols Commitment Protocols

Commitment Protocols

C(x, y, p, q) In Commitment protocols [Yolum and Singh, 2002] By performing some actions the agents socially commit to do (or achieve) something The expectation is that at the end all commitments are satisfied Characteristics they respect the agents’ autonomy they allow agents for flexible behaviours (what rather than how) they are verifiable However, Commitment Protocols do not account for Patterns of Interaction

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 6 / 41

Interaction Protocols Commitment Protocols

Commitment Protocols

C(x, y, p, q) In Commitment protocols [Yolum and Singh, 2002] By performing some actions the agents socially commit to do (or achieve) something The expectation is that at the end all commitments are satisfied Characteristics they respect the agents’ autonomy they allow agents for flexible behaviours (what rather than how) they are verifiable However, Commitment Protocols do not account for Patterns of Interaction

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 6 / 41

Interaction Protocols Commitment Protocols

Commitment Protocols

C(x, y, p, q) In Commitment protocols [Yolum and Singh, 2002] By performing some actions the agents socially commit to do (or achieve) something The expectation is that at the end all commitments are satisfied Characteristics they respect the agents’ autonomy they allow agents for flexible behaviours (what rather than how) they are verifiable However, Commitment Protocols do not account for Patterns of Interaction

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 6 / 41

Interaction Protocols Patterns of Interaction

Patterns of interaction

They can be used for expressing requirements on the evolution of the interaction (e.g. agreements, norms, rules, conventions...) improving coordination They bring to the same state but...

• ne may wish to say that only payment followed by shipment is acceptable

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 7 / 41

Main Contributions

Main Contributions

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 8 / 41

Interaction and coordina- tion among agents

Main Contributions

2CL Protocols

Extend commitment protocols with the possibility of expressing patterns of interaction The specification is based on Constraints and Commitments: Commitments: Capture contractual/social relations among the interacting parties Constraints: Are used to represent patterns of interaction that the interaction is desired to respect.

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 9 / 41 · M. Baldoni, C. Baroglio, E. Marengo, and V. Patti. Constitutive and Regulative Specifications

• f Commitment Protocols: a Decoupled Approach. ACM Transactions on Intelligent Systems

and Technology, Special Issue on Agent Communication, To appear. · M. Baldoni, C. Baroglio, and E. Marengo. Behavior-oriented Commitment- based Protocols. In

• Proc. of ECAI 2010.

· M. Baldoni, C. Baroglio, and E. Marengo. Constraints among Commitments: Regulative Spec- ification of Interaction Protocols. In Proc. of AC 2010.

Main Contributions

Main Contributions

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 10 / 41

Interaction and coordina- tion among agents Theoretical Framework

Main Contributions

Main Contributions

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 10 / 41

Interaction and coordina- tion among agents Theoretical Framework Evaluation

Main Contributions

Main Contributions

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 10 / 41

Interaction and coordina- tion among agents Theoretical Framework Adaptation/Grafting Evaluation

Main Contributions

Main Contributions

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 10 / 41

Interaction and coordina- tion among agents Theoretical Framework Adaptation/Grafting Protocol Engineering, Design and Analysis Evaluation

2CL Protocols Specification

Interaction among Agents

A 2CL interaction protocol P is a tuple Ro: interacting roles F: set of literals (facts and commitments) s0: initial state A: set of protocol actions Cst: set of constraints defining the patterns of interaction

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 11 / 41

2CL Protocols Specification Constitutive Specification

Constitutive Specification

X means Y if Cond The set of actions A, defined on Ro and F, forms the Constitutive Specification [Searle, 1995] of a 2CL protocol Count-as relation X is a physical event, Y is a (set of) social event(s), Cond is the condition under which X acquires the specified meaning means captures a count-as relation between physical and social events social events correspond to operations on facts and commitments

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 12 / 41

2CL Protocols Specification Constitutive Specification

Constitutive Specification

X means Y if Cond The set of actions A, defined on Ro and F, forms the Constitutive Specification [Searle, 1995] of a 2CL protocol Count-as relation X is a physical event, Y is a (set of) social event(s), Cond is the condition under which X acquires the specified meaning means captures a count-as relation between physical and social events social events correspond to operations on facts and commitments

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 12 / 41

2CL Protocols Specification Constitutive Specification

Example

Constitutive Specification of CNET

(a) cfp means create(C(i, p, proposal, assigned ∨ send reject)) (b) proposal means create(C(p, i, assigned, solved)) if ¬solved (c) send refusal means refused task if cfp ∧ ¬solved (d) send accept means assigned (e) send reject means release(C(p, i, assigned, solved)) if proposal (f) send done means solved (g) failure means cancel(C(p, i, assigned, solved))∧ cancel(C(p, i, solved))

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 13 / 41

2CL Protocols Specification Constraints Specification

Constraints Specification

dnf1 op dnf2 The set of constraints Cst, defined on Ro and on F, extends the regulative specification [Searle, 1995] of a commitment protocol. 2CL: the Constraints among Commitments Language Allows to express patterns as constraints among facts and commitments dnf1 and dnf2 are disjunctive normal form formulas; op is a 2CL constraint It is a declarative language

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 14 / 41

2CL Protocols Specification Constraints Specification

Constraints Specification

dnf1 op dnf2 The set of constraints Cst, defined on Ro and on F, extends the regulative specification [Searle, 1995] of a commitment protocol. 2CL: the Constraints among Commitments Language Allows to express patterns as constraints among facts and commitments dnf1 and dnf2 are disjunctive normal form formulas; op is a 2CL constraint It is a declarative language

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 14 / 41

2CL Protocols Specification 2CL

The Constraints among Commitments Language

Operator Meaning Relation Operators dnf1 correlate dnf2 In an execution where dnf1 occurs, also dnf2 must occur but there is no temporal relation between the two. dnf1 not correlate dnf2 If dnf1 occurs in some execution, dnf2 must not occur. dnf1 co-exist dnf2 It captures the mutual correlation dnf1 correlate dnf2 and dnf2 correlate dnf1. dnf1 not co-exist dnf2 This captures the mutual exclusion of dnf1 and dnf2: both dnf1 not correlate dnf2 and dnf2 not correlate dnf1 hold. Temporal Operators dnf1 response dnf2 If dnf1 occurs, dnf2 must hold at least once afterwards (or in the same state). It does not matter if dnf2 already held before dnf1. dnf1 not response dnf2 If dnf1 holds, dnf2 cannot hold in the same state or after. dnf1 before dnf2 dnf2 cannot hold until dnf1 becomes true. Afterwards, it is not necessary that dnf2 becomes true. dnf1 not before dnf2 In case dnf2 becomes true, dnf1 cannot hold beforehand. dnf1 cause dnf2 It is the conjunction of response and before relations: dnf1 response dnf2 and dnf1 before dnf2. dnf1 not cause dnf2 It is the conjunction of response and before negative rela- tions: dnf1 not response dnf2 and dnf1 not before dnf2. Strong Sequence dnf1 premise dnf2 dnf1 must hold in the state immediately preceding one state in which dnf2 holds. dnf1 not premise dnf2 dnf1 must never hold in a state that immediately precedes

• ne where dnf2 holds.

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 15 / 41

2CL Protocols Specification 2CL

Example

Constraints Specification of CNET

(c1) cfp before refused task or C(p, i, assigned, solved) (c2) C(p, i, assigned, solved) before send reject or assigned (c3) assigned before solved

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 16 / 41

2CL Protocols Specification 2CL

Example

Constraints Specification of CNET

(c1) cfp before refused task or C(p, i, assigned, solved) (c2) C(p, i, assigned, solved) before send reject or assigned (c3) assigned before solved

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 16 / 41

2CL Protocols Specification 2CL

Example

Constraints Specification of CNET

(c1) cfp before refused task or C(p, i, assigned, solved) (c2) C(p, i, assigned, solved) before send reject or assigned (c3) assigned before solved

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 16 / 41

2CL Protocols Specification 2CL

2CL Constraints Graphical representation

Declarative Approaches are accused of being not very intuitive (lowering their usability) [Miller and McGinnis, 2008] lack of graphical intuitive representations oriented to designers Graphical convention It is inspired by Declare [van der Aalst and Pesic, 2006, Montali, 2009] and DCML [Baldoni et al., 2007, Baldoni et al., 2011b] representations dot represents the “triggering condition” arrow represents the temporal nature of the constraint negated operators are crossed by a line

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 17 / 41 · M. Baldoni, C. Baroglio, E. Marengo, and V. Patti. Constitutive and Regulative Specifications

• f Commitment Protocols: a Decoupled Approach. ACM Transactions on Intelligent Systems

and Technology, Special Issue on Agent Communication, To appear. · M. Baldoni, C. Baroglio, and E. Marengo. Constraints among Commitments: Regulative Spec- ification of Interaction Protocols. In Proc. of AC 2010.

2CL Protocols Specification 2CL

2CL Constraints Graphical representation

Declarative Approaches are accused of being not very intuitive (lowering their usability) [Miller and McGinnis, 2008] lack of graphical intuitive representations oriented to designers Graphical convention It is inspired by Declare [van der Aalst and Pesic, 2006, Montali, 2009] and DCML [Baldoni et al., 2007, Baldoni et al., 2011b] representations dot represents the “triggering condition” arrow represents the temporal nature of the constraint negated operators are crossed by a line

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 17 / 41 · M. Baldoni, C. Baroglio, E. Marengo, and V. Patti. Constitutive and Regulative Specifications

• f Commitment Protocols: a Decoupled Approach. ACM Transactions on Intelligent Systems

and Technology, Special Issue on Agent Communication, To appear. · M. Baldoni, C. Baroglio, and E. Marengo. Constraints among Commitments: Regulative Spec- ification of Interaction Protocols. In Proc. of AC 2010.

2CL Protocols Specification 2CL

Graphical representation: Relation Operators

Constraint Representation Correlation l1 correlate l2 l1 l2 l1 not correlate l2 l1 l2 Co-existence l1 co-exist l2 l1 l2 l1 not co-exist l2 l1 l2

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 18 / 41

2CL Protocols Specification 2CL

Graphical representation: Temporal Operators

Constraint Representation Response l1 response l2 l1 l2 l1 not response l2 l1 l2 Before l1 before l2 l1 l2 l1 not before l2 l1 l2 Cause l1 cause l2 l1 l2 l1 not cause l2 l1 l2 l1 l2 Premise l1 premise l2 l1 l2 l1 not premise l2 l1 l2

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 19 / 41

2CL Protocols Specification 2CL

Graphical representation: Drawing Formulas

Literal representation

l

Conjunction of literals . . . l1 ln cf = l1 ∧ . . . ∧ ln Disjunctive normal form formula ln l1 . . . . . . cfi dnf = l1 ∨ . . . ∨ cfi ∨ . . . ∨ ln Exclusive Disjunctive normal form formula ln l1 . . . . . . cfi dnf = l1 xor . . . xor cfi xor . . . xor ln

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 20 / 41

2CL Protocols Specification 2CL

Graph of Constraints: no-flow-in-flow

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 21 / 41

2CL Protocols Specification 2CL

Graph of Constraints: no-flow-in-flow

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 22 / 41

2CL Protocols Specification Comparison with other Proposals

Comparison with other Proposals

Current Proposals

Do not account for patterns of interaction [Chopra and Singh, 2008, Chopra, 2009] Focus on regulative aspects [Chesani et al., 2009, Montali et al., 2010, Torroni et al., 2009] Patterns are hidden inside actions definitions [Winikoff et al., 2005, Chopra and Singh, 2006, Kafali and Yolum, 2009] Represent patterns procedurally [Fornara and Colombetti, 2003, Fornara and Colombetti, 2004] Capture some relations expressed among events [Mallya and Singh, 2006] [Singh, 2003, Marengo et al., 2011]

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 23 / 41 M. Baldoni, C. Baroglio, and E. Marengo. Commitment-based Protocols with Behavioral Rules and Correctness Properties of MAS. In Post- Proc.

• f DALT 2010, Revised Selected and Invited

Papers, LNAI 6619.

Main Contributions

Main Contributions

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 24 / 41

Interaction and coordina- tion among agents Evaluation

Main Contributions

Main Contributions

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 24 / 41

Interaction and coordina- tion among agents Evaluation Adaptation/Grafting

Evaluation

Evaluation

Case Studies OECD Guidelines for private data protection MiFID: Markets in Financial Instruments Directive (investment services off-site)

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 25 / 41 · M. Baldoni, C. Baroglio, E. Marengo, and V. Patti. Grafting Regulations into Business Protocols: Supporting the Analysis of Risks of Violation. In Proc. of RELAW 2011. · M. Baldoni, C. Baroglio, E. Marengo, V. Patti, and F. Capuzzimati. Learn the Rules so you Know How to Break them Properly. In Proc. of WOA 2011. · M. Baldoni, C. Baroglio, V. Patti, and E. Marengo. Supporting the Analysis of Risks

• f Violation in Business Protocols: the MiFID Case Study. In Information Systems:

Crossroads for Organization, Management, Accounting and Engineering. Springer,

• 2012. Best Track Paper Award.

Evaluation

Grafting of new Regulations

Data Flow Protocol

(a) ask data (b) send data (c) refuse data

OECD Guidelines

(d) periodically verify accuracy (e) check accuracy (f) verify purpose (g) notify owner

Constraints specifying the grafting

(c1) purpose verified −

⊲

• sent data

(c2) accuracy verified −

⊲

• sent data

(c3) sent data • −

⊲ owner notified

(c4) purpose verified −

⊲

• refuse data

(c5) accuracy verified −

⊲

• refuse data

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 26 / 41

Evaluation

Grafting of new Regulations

1 start 4 5 verify_purpose !c2 7 check_accuracy !c1 6 check_accuracy verify_purpose 12 13 check_accuracy 15 verify_purpose !c5 16 check_accuracy !c4 verify_purpose 3 notify_owner !c2 8 verify_purpose !c2 10 check_accuracy !c1 notify_owner !c2 9 check_accuracy notify_owner !c1 verify_purpose notify_owner 2 refuse_data !c4 send_data !c2 11 verify_purpose 17 check_accuracy refuse_data !c5 send_data !c2 14 check_accuracy send_data refuse_data refuse_data !c4 send_data !c1 verify_purpose ask_data 18 periodically_verify_accuracy ask_data

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 27 / 41 · M. Baldoni, C. Baroglio, E. Marengo, and V. Patti. Grafting Regulations into Business Protocols: Supporting the Analysis of Risks of Violation. In Proc. of RELAW 2011. · M. Baldoni, C. Baroglio, V. Patti, and E. Marengo. Supporting the Analysis of Risks

• f Violation in Business Protocols: the MiFID Case Study. In Information Systems:

Crossroads for Organization, Management, Accounting and Engineering. Springer,

• 2012. Best Track Paper Award.

Evaluation MiFID

Grafting of new Regulations

Sale Protocol

(a) propose solution (b) accept proposal (c) introduce investor (d) prepare contract (e) sign contract (f) countersign contract (g) notify (h) invest (i) withdraw

Introducing MiFID

(j) interview (k) profile (l) classify products (m) evaluate (n) verify

Constraints specifying the Grafting

(c1) document supplied −

⊲

• C(bank, inv, invest)

(c2) document supplied −

⊲

• C(inv, bank, prepare contract, sign contract)

∧C(inv, bank, sign contract) (c3) interview −

⊲

• introduce investor

(c4) verify −

⊲

• countersign contract

(c5) profile −

⊲

• C(fp, inv, proposed riskL)

(c6) evaluate −

⊲

• proposed riskL

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 28 / 41

Evaluation MiFID

Labelled Graph after MiFID

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 29 / 41

Main Contributions

Main Contributions

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 30 / 41

Interaction and coordina- tion among agents Adaptation/Grafting Protocol Engineering, Design and Analysis Evaluation

Support to usability Methodology

2CM: the Constraints among Commitments Methodology

2CM supports the analyst in: Protocol Specification Protocol Composition Protocol Specialization It adapts the Amoeba [Desai et al., 2009] methodology to handling 2CL protocols and extends it for protocol Specialization

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 31 / 41

Support to usability Tools

Tool

It is realized as an Eclipse plug-in: Translating specification files Support for protocol specification Generation and Visualization of the Labelled Graph of Possible Interactions Exploration of the labelled graph:

• ne node at a time;

legal paths; illegal paths; content of states.

http://di.unito.it/2cl

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 32 / 41

• M. Baldoni, C. Baroglio, F. Capuzzimati, E. Marengo, and V.
• Patti. A Generalized Commitment Machine for 2CL Protocols

and its Implementation. Proc. of DALT 2012.

Support to usability Tools

Labelled Graph of Interactions

Aims at supporting the analysis of the specification (e.g. the Analysis of risks of violations) It is realized in tuProlog It extends the enhanced commitment machine by Winikoff et al. [Winikoff et al., 2005, DALT] Enhanced Commitment Machine features:

Generation of reachable states Commitments life-cycle

Additionally we evaluate protocol constraints

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 33 / 41

Main Contributions

Main Contributions

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 34 / 41

Interaction and coordina- tion among agents Theoretical Framework Adaptation/Grafting Protocol Engineering, Design and Analysis Evaluation

2CL-GCM

Theoretical Framework

2CL-GCM: 2CL-Generalized Commitment Machine 2CL-GCM extends the Generalized Commitment Machine (GCM) by Singh [Singh, 2007, IJCAI] GCM allows to infer transitions among the states

Given a set of states Given a set of actions

2CL-GCM extends GCM

accounting for a set of constraints constraints are used to characterise a path of the 2CL-GCM

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 35 / 41

• M. Baldoni, C. Baroglio, F. Capuzzimati, E. Marengo, and V.
• Patti. A Generalized Commitment Machine for 2CL Protocols

and its Implementation. Proc. of DALT 2012.

2CL-GCM

LTL interpretation of 2CL constraints

Protocol constraints Cst To be a path of a 2CL-GCM a sequence of states must satisfy the constraints in Cst To this aim we associate an LTL interpretation (ϕltl) to each 2CL

• perator

Relation Operator LTL interpretation ϕltl Relation Operators Correlation A correlate B ♦A → ♦B A not correlate B ♦A → ¬♦B Co-existence A co-exist B ϕltl (A correlate B) ∧ ϕltl (B correlate A) A not co-exist B ϕltl (A not correlate B) ∧ ϕltl (B not correlate A) Temporal Operators Response A response B (A → ♦B) A not response B (A → ¬♦B) Before A before B ¬B ∪ A A not before B (♦B → ¬A) Cause A cause B ϕltl (A response B) ∧ ϕltl (A before B) A not cause B ϕltl (A not response B) ∧ ϕltl (A not before B) Strong Sequence Premise A premise B (B → A) A not premiseB (B → ¬A) Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 36 / 41

• M. Baldoni, C. Baroglio, and E. Marengo.

Behavior-oriented Commitment- based

• Protocols. In Proc. of ECAI 2010.

2CL-GCM

2CL-Generalized Commitment Machine (2CL-GCM)

2CL-GCM A 2CL-GCM is a tuple P = S, A, s0, ∆, G, Cst, where:

• S is a finite set of states;
• A is a finite set of actions;
• s0 ∈ S is the initial state;
• ∆ is an action theory;
• G ⊆ S is a set of good states;
• Cst is a set of 2CL constraints.

(i) Members of S are logically distinct, that is: ∀s, s′ ∈ S, s ≡ s′; (ii) false ∈ S; and (iii) any state that logically derives a good state is also good.

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 37 / 41

2CL-GCM

Path of a 2CL-GCM

Path of a 2CL-GCM Is a path according to the GCM and It satisfies the LTL interpretation associated to each 2CL constraint

• f the specification

2CL-GCM path Let P = S, A, s0, ∆, G, Cst be a 2CL-GCM. Let τ = (τ0, a0, τ1), . . . be an infinite sequence of triples and T(τ) be the corresponding transition

• system. Let inf (τ) be the set of states that occur infinitely often in τ. τ is

a path generated from P when: (i) ∀(τi, ai, τi+1) in τ then τi, τi+1 ∈ S and ai ∈ A and τi

ai

֒ → τi+1 ∈ ∆; and (ii) inf (τ) ∩ G = ∅; and (iii) ∀c ∈ Cst : T(τ), τ0 | =LTL ϕltl(c)

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 38 / 41

Conclusions

Conclusions and Future Work

2CL Protocols Allow for the specification of patterns of interaction in protocol specifications The specification is flexible They foster reuse of the specification by supporting the adaptation of a specification to different contexts

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 39 / 41

Conclusions

Conclusions and Future Work

Ongoing and Future Directions Introduce 2CL constraints as commitment conditions:

along the line of Regula [Marengo et al., 2011]; explicitly identifying a responsible; modifying commitments’ life cycle; notions of safety and control.

Study new functionalities for the tool and explore the adoption of different languages Exploit the A&A meta-model [Baldoni et al., 2010, Baldoni et al., 2011a]:

capturing direct and indirect communication; supporting observability [Baldoni and Baroglio, 2012]; monitoring the interaction.

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 40 / 41

Conclusions

Thanks

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 41 / 41

Conclusions

Baldoni, M. and Baroglio, C. (2012). Some Thoughts about Commitment Protocols. In Baldoni, M., Dennis, L., Mascardi, V., and Vasconcelos, W., editors, Proc. of International Workshop on Declarative Agent Languages and Technologies, DALT 2012, held in conjuction with AAMAS 2012, Valencia, Spain. Baldoni, M., Baroglio, C., Bergenti, F., Boccalatte, A., Marengo, E., Martelli, M., Mascardi, V., Padovani, L., Patti, V., Ricci, A., Rossi, G., and Santi, A. (2010). MERCURIO: An Interaction-oriented Framework for Designing, Verifying and Programming Multi-Agent Systems. In Fornara, N. and Vouros, G., editors, Proc. of the 3rd Multi-Agent Logics, Languages, and Organisations Federated Workshops (MALLOW’10), 11th International Workshop on Coordination, Organization, Institutions and Norms in Multi-Agent Systems (COIN@MALLOW 2010), volume 627, Domain Valpr´ e in Lyon,

• France. CEUR Workshop Proceedings.

Elisa Marengo (UNITO) 2CL Protocols October 19, 2012 41 / 41

Conclusions

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