Specifying and verifying interaction protocols in a temporal action logic

Abstract

In this paper we develop a logical framework for specifying and verifying systems of communicating agents and interaction protocols. The framework is based on Dynamic Linear Time Temporal Logic (DLTL), which extends LTL by strengthening the until operator by indexing it with the regular programs of dynamic logic. The framework provides a simple formalization of the communicative actions in terms of their effects and preconditions and the specification of an interaction protocol by means of temporal constraints. We adopt a social approach to agent communication, where communication can be described in terms of changes in the social relations between participants, and protocols in terms of creation, manipulation and satisfaction of commitments among agents. The description of the interaction protocol and of communicative actions is given in a temporal action theory, and agent programs, when known, can be specified as complex actions (regular programs in DLTL). The paper addresses several kinds of verification problems (including the problem of verifying compliance of agents with the protocol), which can be formalized either as validity or as satisfiability problems in the temporal logic and can be solved by model checking techniques. In particular, we show that the verification of the compliance of an agent with the protocol requires to move to the logic DLTL ⊗ , the product version of DLTL.

A Generalized Commitment Machine for 2CL Protocols and Its Implementation

“…Further approaches rely on temporal logics to give a formal semantics to commitments and to the protocols defined upon them. Among these, [13] uses DLTL. All these approaches allow the inference of the possible executions of the protocol, but, differently than [4], all of them consider as the only regulative aspect of the protocol the regulative value of the commitments.…”

Reasoning about actions with Temporal Answer Sets

“…We observe that the verification that a domain description D is well defined can be done by adding to the domain description a static law 2(undef ined fluent not f^not ¬f ), for each fluent literal f , and by verifying that there are no estensions in which 3undef ined fluent holds in the initial state. Among the other reasoning task which can be addressed by checking the satisfiability/validity of formulas in a temporal action theory, we want to mention the verification problems arising from the area of multiagent protocol verification (Giordano et al 2007), as well as the verification of the compliance of business processes to norms. We refer to (D'Aprile et al 2010) for a formulation of this problem as a problem of reasoning about actions with temporal answer sets.…”

“…In general, temporal formulas can be usefully exploited both in the specification of a domain and in the verification of its properties. This has been done, for instance, for modeling the interaction of services on the web (Pistore et al 2005), as well as for the specification and verification of agent communication protocols (Giordano et al 2007). Recently, Claßen and Lakemeyer (Claßen and Lakemeyer 2008) have introduced a second order extension of the temporal logic CTL*, ESG, to express and reason about non-terminating Golog programs.…”

Commitment-Based Protocols with Behavioral Rules and Correctness Properties of MAS

“…The constitutive specification gives the semantics of actions, while the regulative one rules the flow of execution. The regulative specification, encoding the behavioral rules, however, is not explicitly represented in commitment-based approaches like [17,15,36,39,23,41], where only actions are represented.…”

“…When there is the need to constrain the behavior of agents, they use preconditions to the (non-)executability of the actions. This solution (which is adopted also by other works, like [23,41,42,15,39]) is characterized by a strong localization of the regulative specification; the constitutive and the regulative specifications are indistinguishable (being both based on actions) and action become dependant on the protocol they are used in. This limits the openness of the system and in particular complicates the re-use of software (the agents' actions).…”