Then we present defeasible reasoning concepts using the defeasible logic formalism and dprolog logical implementation of defeasible logic. We talked about aristotelian logic and how it is useful to ai in another post but twovalued logic that recognises only true or false statements cannot easily deal with natural language, where statements are not clearly true or false, but can have other values inbetween, like. Inspired by legal reasoning, this paper presents a semantics and proof theory of a system for defeasible argumentation. An important feature of the system is that these priorities are not fixed, but are. This last approach is used in dprolog nute 1988, defeasible logic nute 1992, extensions of defeasible logic antoniou et al. Defeasible logic nute, 1992, extensions of defeasible logic antoniou et a l. This statement would not stand up to rigorous reasoning, because the earth could. Defeasible logic is a nonmonotonic logic proposed by donald nute to formalize defeasible reasoning. Pdf computing temporal defeasible logic researchgate. The work reported here introduces defeasible logic programming delp, a formalism that combines results of logic programming and defeasible argumentation. A characterization of collective con ict for defeasible. Our results show that the former has a strictly stronger expressive power. This book reports on the development and validation framework to support argumentation in semantic web applications springer theses naeem khalid. A delpprogram p is a set of facts, strict rules and defeasible rules.
In defeasible logic, there are three different types of propositions. We begin with agentoriented programming language giving focus to agentspeak language extension found in jason platform, which is the language used to make our approach within the practice. Defeasible logic programming and belief revision uns. Pdf programming cognitive agents in defeasible logic. A defeasible logic programmingbased framework to support argumentation in semantic web applications springer theses naeem khalid janjua on. Find, read and cite all the research you need on researchgate. A redefinition of arguments in defeasible logic programming. I present an alternative account of defeasible entailment and show how logic programming offers a paradigm in which the distinction can be captured, allowing for the modeling of a larger range of types of defeat. Defeasible logic programming delp is an argumentationbased reasoning tool that allows users to contemplate reasons for and against certain conclusionsthe warrant status of literals in the. Delp provides the possibility of representing information in the form of weak rules in a declarative manner, and a defeasible argumentation inference. Prolog programming in logic is a representative logic language. Execution of a logic program is a theorem proving process.
As a consequence, the notion of warrant for temporal literals is slightly different from that of delp as. The model is a sequence of moves in a collaborative group inquiry in which parties take turns making assertions. This is possible through a natural extension of the declarative and procedural semantics of. It is based on the concept of a derivation or proof in d f,r. Defeasible logic programming 8 dlp is an extension of logic programming capturing commonsense reasoning features, that are dicult to express in traditional logic programming. Pdf a defeasible logic programming system for the web. Defeasible logic is a rulebased nonmonotonic logic, with both strict and defeasible rules, and a priority relation on rules. The work reported here introduces defeasible logic programming delp, a formalism that combines results of logic programming and defeasible.
Defeasible logic, originally created by donald nute with a particular concern about efficiency and implementation, is a simple and efficient rule based nonmonotonic formalism. There are three rule types in many defeasible logics. Arguments are expressed in a logicprogramming language with both weak and strong negation, conflicts between arguments are decided with the help of priorities on the rules. Argumentbased extended logic programming with defeasible. Defeasible logic, and sceptical logic programming without negation as failure lpwnf.
Artificial intelligence research and development lab. A defeasible deontic reasoning system based on annotated. Elements of defeasible logic programming defeasible logic programming delp combines results of logic programming and defeasible argumentation. Integrating defeasible argumentation with fuzzy art neural.
On warranted inference in possibilistic defeasible logic. In fact, defeasible reasoning in the form of courteous logic programs. The original defeasible logic is ambiguity blocking, but we can also define an. Embedding defeasible logic programs into generalized logic programs. The system is fully implemented and is available online lidia 2007, and a brief explanation of its theory is included below. Programs are written in the language of some logic. Defeasible logic is a nonmonotonic logic designed to be implemented in prolog 4, 64. Propositional defeasible logic has linear complexity. Embedding defeasible logic programs into generalized logic. This webpage provides a web service for defeasible logic programming delp. Instead, default reasoning is modelled by rules and a priority relation among them. Such reasoning is, among others, useful for ontology integration, where conflicting information arises naturally.
This paper relates the defeasible logic programming delp framework and its semantics sem delp to classical logic programming frameworks. We show that inference in the propositional form of the logic can be performed in linear time. A in these rules are considered to represent classical negation. Defeasible logic programming delp is a formalism that extends declarative programming to capture defeasible reasoning. A defeasible logic program is a set p 77, a of hornlike clauses, where 11 and a stand for sets of.
Embedding defeasible logic into logic programming 3 the paper is organised as follows. Argumentation semantics for defeasible logic oxford academic. Defeasible reasoning is a useful tool when many facts about a situation are unknown. Abstract inspired by legal reasoning, this paper presents a semantics and proof theory of a system for defeasible argumentation. Embedding defeasible logic into logic programming delab. Defeasible reasoning reasoning with many unknown factors. Arguments are expressed in a logicprogramming language with both weak and strong negation. Defeasible logic is extended to programming languages for cognitive agents with preferences and actions for planning. Conflicts between arguments are decided with the help of priorities on the rules. Introduction and motivations possibilistic defeasible logic programming pdelp 10 is a logic programming lan.
Defeasible reasoning is done using an argumentation formalism. Delp stands for defeasible logic programming, a knowledge representation language, where defeasible and nondefeasible rules can be expressed. Recently there has been increased interest in modelling default reasoning by means of rules. Strong and default negation in defeasible logic programming. An example of defeasible reasoning would be the statement that the sun will rise tomorrow. Defeasible logic programming, or delp for short, provides a computational reasoning system that uses an argumentation engine to obtain answers from a knowledge base represented using a logic programming language extended with defeasible rules that stem from the work reported in simari and simari and loui. Argument theory change applied to defeasible logic. Sections 2 and 3 present the basics of defeasible logic and logic programming semantics, respectively. Defeasible logic programming delp 3 is a reasoning framework based on logic programming and defeasible argumentation with a working implementation.
Defeasible logic programming an argumentative approach 97 knowledge. Over the year the logic has been developed and extended, and several variants have been proposed. We will also discuss briey in this paper how to extend delp for con sidering default negation. The resulting approach is suitable for representing agents knowledge and for providing an argumentation based reasoning mechanism to agents. Defeasible reasoning and logic programming springerlink. A first approach to argumentbased recommender systems. Reasoning about knowledge using defeasible logic in this paper, the carneades argumentation system is extended to represent a procedural view of inquiry in which evidence is marshalled to support or defeat claims to knowledge.
It is distinct from fuzzy logic and probabilistic logic, addressing a different set of problems. Citeseerx document details isaac councill, lee giles, pradeep teregowda. Philosophical foundations of deontic logic and the logic of defeasible conditionals, carlos alchourron, in deontic logic in computer science. Defeasible logic versus logic programming without negation as failure g.
The presented language can manage defeasible reasoning, allowing the. In contrast to this, in normal logic programming nlp, there is only one kind. In this paper, we provide a theoretical framework for a defeasible deontic reasoning system based on annotated logic programming, we propose an annotated logic program called an evalpsn extended vector annotated logic program with strong negation to formulate a defeasible deontic reasoning proposed by d. In delp, we distinguish between two different sorts of rules. Relating defeasible and normal logic programming through. Assuring safety in an air tra c control system with. Defeasible logic programming an argumentative approach. Ana gabriela maguitman computer science department indiana university bloomington, in 474057104,usa. The work reported here introduces defeasible logic programming delp, a formalism that combines results of logic. Compilation techniques for defeasible logic programs. Download a defeasible logic programmingbased framework. In 29, 2 we have introduced a family of metaprograms for. Its inference mechanism, upon a query on a literal in a program, answers by indicating whether or not it is warranted in an argumentation process.
An approach for argumentationbased reasoning using. In this article, we propose a recursive semantics for warranted formulas in a general defeasible logic argumentation framework by formalizing a notion of collective nonbinary conflict among arguments. We define rulebased agent the ories that contain preferences and actions. Theory and practice of logic programming most cited. Advantages of defeasible logic include conciseness and correct handling of the passage of time. Pdf automating defeasible reasoning with logic programming. Pdf we investigate the complexity of temporal defeasible logic, and propose. Section 4 presents our translation of defeasible theories in logic programs, while section 5 contains the main results. Defeasible logic versus logic programming without negation. Defeasible reasoning is a rulebased approach for efficient reasoning with incomplete and inconsistent information. In this paper we compare the expressive power of two approaches in this family of logics.
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