Logical foundations and complexity of 4QL, a query language with unrestricted negation

Maluszynski, Jan; Szałas, Andrzej

doi:10.3166/jancl.21.211-232

Cited by 23 publications

(15 citation statements)

References 28 publications

(34 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The following theorems can be proved similarly to analogous results for 4QL [34][35][36] and 4QL Bel [5].…”

Section: Tractability Of the Approachmentioning

confidence: 60%

“…ACTLOG belongs to the 4QL family of four-valued, rule-based languages. It builds on 4QL Bel [5], which, in turn, extends the 4QL rule language [34][35][36]. While 4QL already permits to flexibly resolve/disambiguate 3i at any level of reasoning, 4QL Bel includes means for doxastic reasoning by specifying paraconsistent belief bases and referring to them in rules.…”

Section: Actions In Informationally Complex Environmentsmentioning

confidence: 99%

See 1 more Smart Citation

A paraconsistent approach to actions in informationally complex environments

Białek

Dunin-Keplicz

Szałas

2019

Ann Math Artif Intell

View full text Add to dashboard Cite

Contemporary systems situated in real-world open environments frequently have to cope with incomplete and inconsistent information that typically increases complexity of reasoning and decision processes. Realistic modeling of such informationally complex environments calls for nuanced tools. In particular, incomplete and inconsistent information should neither trivialize nor stop both reasoning or planning. The paper introduces ACT-LOG, a rule-based four-valued language designed to specify actions in a paraconsistent and paracomplete manner. ACTLOG is an extension of 4QL Bel , a language for reasoning with paraconsistent belief bases. Each belief base stores multiple world representations. In this context, ACTLOG's action may be seen as a belief bases' transformer. In contrast to other approaches, ACTLOG actions can be executed even when the underlying belief base contents is inconsistent and/or partial. ACTLOG provides a nuanced action specification tools, allowing for subtle interplay among various forms of nonmonotonic, paraconsistent, paracomplete and doxastic reasoning methods applicable in informationally complex environments. Despite its rich modeling possibilities, it remains tractable. ACTLOG permits for composite actions by using sequential and parallel compositions as well as conditional specifications. The framework is illustrated on a decontamination case study known from the literature.

show abstract

“…The following theorems can be proved similarly to analogous results for 4QL [34][35][36] and 4QL Bel [5].…”

Section: Tractability Of the Approachmentioning

confidence: 60%

Section: Actions In Informationally Complex Environmentsmentioning

confidence: 99%

A paraconsistent approach to actions in informationally complex environments

Białek

Dunin-Keplicz

Szałas

2019

Ann Math Artif Intell

View full text Add to dashboard Cite

show abstract

“…Our approach is strongly influenced by ideas underlying 4QL: a four-valued paraconsistent query language introduced by Małuszyński and Szałas (see [16], [17] and Section V for details) 1 . 4QL supports a modular and layered architecture, providing simple, yet powerful constructs for knowledge completion using lightweight forms of well-known nonmonotonic techniques (like default reasoning, autoepistemic reasoning, defeasible reasoning, the (Local) Closed World Assumption).…”

Section: B Why 4ql: Realistic Representation and Tractabilitymentioning

confidence: 99%

Computationally-Friendly Argumentation Schemes

Keplicz

Strachocka

2014

2014 IEEE/WIC/ACM International Joint Conferences on Web Intelligence (WI) and Intelligent Agent Technologies (IAT)

View full text Add to dashboard Cite

In an agent activity both paradigmatic aspects of communication and reasoning can be naturally enriched by argumentation. The contribution of this research is a computationallyfriendly framework for formalizing paraconsistent argumentation schemes in information-rich environments.This goal is achieved by extending agent's reasoning capabilities with non-deductive methods like argumentation skills. We provide a generic paraconsistent program template permitting for implementation of various argumentation schemes. To do this, we appeal to techniques specific for the four-valued framework of 4QL, the rule-based, DATALOG ¬¬ -like query language. Although dealing with paraconsistency in argumentation schemes is not a new subject, our computational approach takes advantage of the tractability of 4QL. The paper concludes with an example of the Expert Opinion scheme implemented in 4QL. I. MODELING ASSUMPTIONS A. Realistic Models of AgencyComplex interactions is an immanent property of multiagent systems (MAS). They are vital to all paradigmatic activities like coordination, collaboration and negotiation, which naturally include phases of communication and reasoning. Communication has a long tradition as an important topic in computer science, specifically in (distributed) artificial intelligence and recently in MAS [6], [21]. Starting from fixed communication protocols in distributed systems, we now attempt to approach flexible dialogues among agents (see e.g., [5]).In an agent activity both aspects of communication and reasoning can be naturally enriched by argumentation. Therefore in the current paper we introduce a framework to formalize argumentation schemes. In order to address problems appearing in realistic domains we consider them in the presence of uncertain and inconsistent information, assuming that four types of situations may occur:• fact a holds,• fact a does not hold,• it is not known whether a holds, • information about a is inconsistent. Following Dunin-Kȩplicz and Szałas [11], the way the individual agents deal with conflicting or lacking information is encoded in their epistemic profile (see Section III). In typical multi-agent settings epistemic profile embodies agents' reasoning capabilities. These in turn influence the agent's deductive processes to finally affect their belief structures, i.e., agents' informational stance [11]. Moreover, various agents may reason differently using different methods of information disambiguation. In this research we will show how to augment an agent epistemic profile by such non-deductive reasoning capabilities like argumentation schemes. Supported by the Polish National Science Centre grants 2011/01/B/ST6/02769 and CORE 6505/B/T02/2011/40 B. Why 4QL: Realistic Representation and TractabilityOur approach is strongly influenced by ideas underlying 4QL: a four-valued paraconsistent query language introduced by Małuszyński and Szałas (see [16], [17] and Section V for details) 1 . 4QL supports a modular and layered architecture, providing simple, yet powerful constructs...

show abstract

“…Relevant methods and algorithms have long been investigated for database systems and rule-based expert systems, e.g., [16], but none has been specifically designed for robotics. Query Language 4QL [17] and Boolean Networks (BN) [18] are very similar to our modelling formalism Boolean evolution systems. The former allows a variable to have four values: true, f alse, unknown and inconsistent.…”

Section: Introductionmentioning

confidence: 99%

Verification of logical consistency in robotic reasoning

Veres

2016

Robotics and Autonomous Systems

View full text Add to dashboard Cite

Most autonomous robotic agents use logic inference to keep themselves to safe and permitted behaviour. Given a set of rules, it is important that the robot is able to establish the consistency between its rules, its perception-based beliefs, its planned actions and their consequences. This paper investigates how a robotic agent can use model checking to examine the consistency of its rules, beliefs and actions. A rule set is modelled by a Boolean evolution system with synchronous semantics, which can be translated into a labelled transition system (LTS). It is proven that stability and consistency can be formulated as computation tree logic (CTL) and linear temporal logic (LTL) properties. Two new algorithms are presented to perform realtime consistency and stability checks respectively. Their implementation provides us a computational tool, which can form the basis of efficient consistency checks on-board robots.

show abstract

Logical foundations and complexity of 4QL, a query language with unrestricted negation

Cited by 23 publications

References 28 publications

A paraconsistent approach to actions in informationally complex environments

A paraconsistent approach to actions in informationally complex environments

Computationally-Friendly Argumentation Schemes

Verification of logical consistency in robotic reasoning

Contact Info

Product

Resources

About