Default theory for Well Founded Semantics with explicit negation

2005 ◽  
pp. 339-356 ◽  
Author(s):  
Luís Moniz Pereira ◽  
José Júlio Alferes ◽  
Joaquim Nunes Aparício
Keyword(s):  
Default Theory ◽  
Explicit Negation

Servicers and Mortgage-Backed Securities Default: Theory and Evidence

2010 ◽  
Author(s):  
Brent W. Ambrose ◽  
Anthony B. Sanders ◽  
Abdullah Yavas
Keyword(s):  
Default Theory ◽  
Mortgage Backed Securities

scholarly journals More on Modal Aspects of Default Logic1

1992 ◽  
Vol 17 (1-2) ◽  
pp. 99-116
Author(s):  
V. Wiktor Marek ◽  
Miroslaw Truszczynski
Keyword(s):  
Modal Logic ◽  
Default Logic ◽  
Nonmonotonic Logic ◽  
Default Reasoning ◽  
Default Theory ◽  
Autoepistemic Logic ◽  
The Relationship ◽  
Natural Classes ◽  
Weak Extension

Investigations of default logic have been so far mostly concerned with the notion of an extension of a default theory. It turns out, however, that default logic is much richer. Namely, there are other natural classes of objects that might be associated with default reasoning. We study two such classes of objects with emphasis on their relations with modal nonmonotonic formalisms. First, we introduce the concept of a weak extension and study its properties. It has long been suspected that there are close connections between default and autoepistemic logics. The notion of weak extension allows us to precisely describe the relationship between these two formalisms. In particular, we show that default logic with weak extensions is essentially equivalent to autoepistemic logic, that is, nonmonotonic logic KD45. In the paper we also study the notion of a set of formulas closed under a default theory. These objects are shown to correspond to stable theories and to modal logic S5. In particular, we show that skeptical reasoning with sets closed under default theories is closely related with provability in S5. As an application of our results we determine the complexity of reasoning with weak extensions and sets closed under default theories.

Constraints on extensions of a default theory

2001 ◽  
Vol 16 (4) ◽  
pp. 329-340 ◽  
Author(s):  
Kaile Su
Keyword(s):  
Default Theory

Revision Programs with Explicit Negation

2005 ◽  
pp. 403-414
Author(s):  
Yisong Wang ◽  
Mingyi Zhang
Keyword(s):  
Explicit Negation

Why Won’t You Answer the Question? Mass-Mediated Deception Detection After Journalists’ Accusations of Politicians’ Evasion

2019 ◽  
Vol 69 (6) ◽  
pp. 674-695
Author(s):  
David E Clementson
Keyword(s):  
Process Modeling ◽  
Deception Detection ◽  
Multiple Mediation ◽  
Default Theory ◽  
Default State ◽  
The Media

Abstract Journalists often accuse politicians of dodging questions. Truth-default theory (TDT) predicts that when journalists serve as de facto deception detectors, the audience will process the messaging through a cognitive sequence that lowers the perceived trustworthiness of the politician. Conversely, the public’s perception of the media as being generally hostile and biased in their reporting could make a journalist’s allegation of evasion enhance the politician’s credibility. We constructed political TV interviews in which a journalist falsely accused a politician of evasiveness. Consistent with serial multiple mediation as proposed by TDT, in Study 1 (N = 210 U.S. voters) a journalist’s allegation triggered suspicion, which increased perceived dodging, resulting in voters distrusting the politician. Absent a journalist’s allegation, however, people remained in their truth-default state toward the politician. Study 2 (N = 429) replicated the Study 1 results, and conditional process modeling revealed that the effect was moderated by rumination.

scholarly journals Sequent-Type Calculi for Three-Valued and Disjunctive Default Logic

Axioms ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 84 ◽  
Author(s):  
Sopo Pkhakadze ◽  
Hans Tompits
Keyword(s):  
Proof Theory ◽  
Consistency Condition ◽  
Nonmonotonic Reasoning ◽  
Default Logic ◽  
Inference Process ◽  
Default Theory ◽  
Valid Inference ◽  
The One ◽  
Base Logic ◽  
Selection Of

Default logic is one of the basic formalisms for nonmonotonic reasoning, a well-established area from logic-based artificial intelligence dealing with the representation of rational conclusions, which are characterised by the feature that the inference process may require to retract prior conclusions given additional premisses. This nonmonotonic aspect is in contrast to valid inference relations, which are monotonic. Although nonmonotonic reasoning has been extensively studied in the literature, only few works exist dealing with a proper proof theory for specific logics. In this paper, we introduce sequent-type calculi for two variants of default logic, viz., on the one hand, for three-valued default logic due to Radzikowska, and on the other hand, for disjunctive default logic, due to Gelfond, Lifschitz, Przymusinska, and Truszczyński. The first variant of default logic employs Łukasiewicz’s three-valued logic as the underlying base logic and the second variant generalises defaults by allowing a selection of consequents in defaults. Both versions have been introduced to address certain representational shortcomings of standard default logic. The calculi we introduce axiomatise brave reasoning for these versions of default logic, which is the task of determining whether a given formula is contained in some extension of a given default theory. Our approach follows the sequent method first introduced in the context of nonmonotonic reasoning by Bonatti, which employs a rejection calculus for axiomatising invalid formulas, taking care of expressing the consistency condition of defaults.

scholarly journals There is no item vs. I wish there were an item: Implicit negation causes false recall just as well as explicit negation

PLoS ONE ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. e0215283
Author(s):  
Józef Maciuszek ◽  
Mateusz Polak ◽  
Martyna Sekulak
Keyword(s):  
False Recall ◽  
Explicit Negation

scholarly journals Revisiting Explicit Negation in Answer Set Programming

2019 ◽  
Vol 19 (5-6) ◽  
pp. 908-924
Author(s):  
FELICIDAD AGUADO ◽  
PEDRO CABALAR ◽  
JORGE FANDINNO ◽  
DAVID PEARCE ◽  
GILBERTO PÉREZ ◽  
...  
Keyword(s):  
Answer Set Programming ◽  
Regular Operator ◽  
Strong Negation ◽  
Classical Negation ◽  
Explicit Negation ◽  
Answer Set

AbstractA common feature in Answer Set Programming is the use of a second negation, stronger than default negation and sometimes called explicit, strong or classical negation. This explicit negation is normally used in front of atoms, rather than allowing its use as a regular operator. In this paper we consider the arbitrary combination of explicit negation with nested expressions, as those defined by Lifschitz, Tang and Turner. We extend the concept of reduct for this new syntax and then prove that it can be captured by an extension of Equilibrium Logic with this second negation. We study some properties of this variant and compare to the already known combination of Equilibrium Logic with Nelson’s strong negation.

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