The capability to store data about Business Process (BP) executions in so-called Event Logs has brought to the identification of a range of key reasoning services (consistency, compliance, runtime monitoring, predicti...
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The capability to store data about Business Process (BP) executions in so-called Event Logs has brought to the identification of a range of key reasoning services (consistency, compliance, runtime monitoring, prediction) for the analysis of process executions and process models. Tools for the provision of these services typically focus on one form of reasoning alone. Moreover, they are often very rigid in dealing with forms of incomplete information about the process execution. While this enables the development of ad hoc solutions, it also poses an obstacle for the adoption of reasoning-based solutions in the BP community. In this paper, we introduce the notion of Structured Processes with Observability and Time (SPOT models), able to support incompleteness (of traces and logs), and temporal constraints on the activity duration and between activities. Then, we exploit the power of abduction to provide a flexible, yet computationally effective framework able to reinterpret key reasoning services in terms of incompleteness and observability in a uniform way.
Formalising deontic concepts, such as obligation, prohibition and permission, is normally carried out in a modal logic with a possible world semantics, in which some worlds are better than others. The main focus in th...
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Formalising deontic concepts, such as obligation, prohibition and permission, is normally carried out in a modal logic with a possible world semantics, in which some worlds are better than others. The main focus in these logics is on inferring logical consequences, for example inferring that the obligation O q is a logical consequence of the obligations O p and O (p -> q). In this paper we propose a non-modal approach in which obligations are preferred ways of satisfying goals expressed in first-order logic. To say that p is obligatory, but may be violated, resulting in a less than ideal situation s, means that the task is to satisfy the goal p a s, and that models in which p is true are preferred to models in which s is true. Whereas, in modal logic, the preference relation between possible worlds is part of the semantics of the logic, in this non-modal approach, the preference relation between first-order models is external to the logic. Although our main focus is on satisfying goals, we also formulate a notion of logical consequence, which is comparable to the notion of logical consequence in modal deontic logic. In this formalisation, an obligation O p is a logical consequence of goals G, when p is true in all best models of G. We show how this non-modal approach to the treatment of deontic concepts deals with problems of contrary-to-duty obligations and normative conflicts, and argue that the approach is useful for many other applications, including abductive explanations, defeasible reasoning, combinatorial optimisation, and reactive systems of the production system variety.
We discuss the static verification of declarative Business Processes. We identify four desiderata about verifiers, and propose a concrete framework which satisfies them. The framework is based on the ConDec graphical ...
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We discuss the static verification of declarative Business Processes. We identify four desiderata about verifiers, and propose a concrete framework which satisfies them. The framework is based on the ConDec graphical notation for modeling Business Processes, and on abductive logic programming technology for verification of properties. Empirical evidence shows that our verification method seems to perform and scale better, in most cases, than other state of the art techniques (model checkers, in particular). A detailed study of our framework's theoretical properties proves that our approach is sound and complete when applied to ConDec models that do not contain loops, and it is guaranteed to terminate when applied to models that contain loops.
Many emerging applications in Business Process Management, Clinical Guidelines, Service-Oriented and Multi-Agent Systems, are characterized by distribution, complex interaction and coordination dynamics. Such domains,...
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ISBN:
(纸本)9783319604381;9783319604374
Many emerging applications in Business Process Management, Clinical Guidelines, Service-Oriented and Multi-Agent Systems, are characterized by distribution, complex interaction and coordination dynamics. Such domains, apparently unrelated, all ask for a suitable tradeoff between flexibility and regulation. In this light, compliance checking emerged as an effective way to understand whether an observed course of interaction agrees with what is expected by a model of the system. In this paper, we single out a non exhaustive list of desiderata and challenges for compliance checking applied at runtime. We then argue that methods, tools and techniques of Computational logic, and abductive Reasoning in particular, can be fruitfully exploited to tackle all such challenges in a formally grounded, computationally effective way.
In this paper we argue the case for integrating the distinctive functionalities of logic programs and production systems within an abductive logic programming agent framework. In this framework, logic programs functio...
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ISBN:
(纸本)9783642050817
In this paper we argue the case for integrating the distinctive functionalities of logic programs and production systems within an abductive logic programming agent framework. In this framework, logic programs function as an agent's beliefs and production rules function as the agent's goals. The semantics and proof procedures are based on abductive logic programming. in which logic programs are integrated with integrity constraints that behave like production rules. Similarly to production systems, the proof procedure is an operational semantics, which manipulates the current state of a database, which is modified by actions implemented by destructive assignment. The semantics can be viewed as generating a model, based on the sequence of database states and logic program, which makes the production rules true.
The article introduces a logical framework for negotiation among dishonest agents. The framework relies on the use of abductive logic programming as a knowledge representation language for agents to deal with incomple...
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The article introduces a logical framework for negotiation among dishonest agents. The framework relies on the use of abductive logic programming as a knowledge representation language for agents to deal with incomplete information and preferences. The article shows how intentionally false or inaccurate information of agents can be encoded in the agents' knowledge bases. Such disinformation can be effectively used in the process of negotiation to have desired outcomes by agents. The negotiation processes are formulated under the answer set semantics of abductive logic programming, and they enable the exploration of various strategies that agents can employ in their negotiation. A preliminary implementation has been developed using the ASP-Prolog platform.
SCIFF is a declarative language, based on abductive logic programming, that accommodates forward rules, predicate definitions, and constraints over finite domain variables. Its abductive declarative semantics can be r...
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SCIFF is a declarative language, based on abductive logic programming, that accommodates forward rules, predicate definitions, and constraints over finite domain variables. Its abductive declarative semantics can be related to that of deontic operators;its operational specification is the sound and complete SCIFF proof procedure, defined as a set of transition rules implemented and integrated into a reasoning and verification tool. A variation of the SCIFF proof procedure (g-SCIFF) can be used for static verification of contract properties. The use of SCIFF for business contract specification and verification is demonstrated in a concrete scenario. Encoding of SCIFF contract rules in RuleML accommodates integration of SCIFF with architectures for business contracts.
Despite its potential as a reasoning paradigm in AI applications, abduction has been on the back burner in logicprogramming, as abduction can be too difficult to implement, and costly to perform, in particular if abd...
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ISBN:
(纸本)9783642406690;9783642406683
Despite its potential as a reasoning paradigm in AI applications, abduction has been on the back burner in logicprogramming, as abduction can be too difficult to implement, and costly to perform, in particular if abductive solutions are not tabled. If they become tabled, then abductive solutions can be reused, even from one abductive context to another. On the other hand, current Prolog systems, with their tabling mechanisms, are mature enough to facilitate the introduction of tabling abductive solutions (tabled abduction) into them. The concept of tabled abduction has been realized recently in an abductive logic programming system TABDUAL. Besides tabling abductive solutions, TABDUAL also relies on the dual transformation. In this paper, we emphasize two TABDUAL improvements: (1) the dual transformation by need, and (2) a new construct for accessing ongoing abductive solutions, that permits modular mixes between abductive and non-abductive program parts. We apply subsequently these improvements on two distinct problems, and evaluate the performance and the scalability of TABDUAL on several benchmarks on the basis of these problems, by examining four TABDUAL variants.
Abduction as reasoning paradigm has been much explored in Artificial Intelligence, but not yet taken up by decision making as much as its potential warrants. Indeed, abduction permits the generation of hypothetical kn...
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ISBN:
(纸本)9781614992646;9781614992639
Abduction as reasoning paradigm has been much explored in Artificial Intelligence, but not yet taken up by decision making as much as its potential warrants. Indeed, abduction permits the generation of hypothetical knowledge based scenarios, about which one can then equate decisions. One reason for this state of affairs is that abduction is difficult to implement efficaciously, even by experts, which entails that abductive systems are not readily available for decision making. Our concept of tabled abduction mitigates this, in the abductive logic programming system TABDUAL. The contribution of this paper is three-fold: (1) We discuss some TABDUAL improvements towards its more practical use, particularly in decision making, (2) We show that declarative debugging can be viewed as abduction in logicprogramming, thus showing another potential of abduction for decision making, and (3) We describe how TABDUAL can be applied in decision making and examine its benefit.
SCIFF is a framework thought to specify and verify interaction in open agent societies. The SCIFF language is equipped with a semantics based on abductive logic programming;SCIFF's operational component is a new a...
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SCIFF is a framework thought to specify and verify interaction in open agent societies. The SCIFF language is equipped with a semantics based on abductive logic programming;SCIFF's operational component is a new abductive logic programming proof procedure, also named SCIFF, for reasoning with expectations in dynamic environments. In this article we present the declarative and operational semantics of the SCIFF language, and the termination, soundness, and completeness results of the SCIFF proof procedure, and we demonstrate SCIFF's possible application in the multiagent domain.
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