Classical and quantum satisfiability

We present the linear algebraic definition of QSAT and propose a direct logical characterization of such a definition. We then prove that this logical version of QSAT is not an extension of classical satisfiability problem (SAT). This shows that QSAT does not allow a direct comparison between the complexity classes NP and QMA, for which SAT and QSAT are respectively complete.Comment: In Proceedings LSFA 2011, arXiv:1203.542

The Universe of Approximations

AbstractThe idea of approximate entailment has been in [13] as a way of modeling the reasoning of an agent with limited resources. They proposed a system in which a family of logics, parameterized by a set of propositional letters, approximates classical logic as the size of the set increases.In this paper, we take the idea further, extending two of their systems to deal with full propositional logic, giving them semantics and sound and complete proof methods based on tableaux. We then present a more general system of which the two previous systems are particular cases and show how it can be used to formalize heuristics used in theorem proving

Coherence of probabilistic constraints on Nash equilibria

In this work, we first deal with the modeling of game situations that reach one of possibly many Nash equilibria. Before an instance of such a game starts, an external observer does not know, a priori, what is the exact profile of actions – constituting an equilibrium – that will occur; thus, he assigns subjective probabilities to players’ actions. Such scenario is formalized as an observable game, which is a newly introduced structure for that purpose. Then, we study the decision problem of determining if a given set of probabilistic constraints assigned a priori by the observer to a given game is coherent, called the PCE-COHERENCE problem. We show several results concerning algorithms and complexity for PCE-COHERENCE when pure Nash equilibria and specific classes of games, called GNP-classes, are considered. In this context, we also study the computation of maximal and minimal probabilistic constraints on actions that preserves coherence. Finally, we study these problems when mixed Nash equilibria are allowed in GNP-classes of 2-player games.info:eu-repo/semantics/publishedVersio

Inteligência Artificial e os rumos do processamento do português brasileiro

Neste artigo apresentamos um posicionamento sobre a área de processamento de língua natural em português, seus desenvolvimentos desde o princípio até a explosão de aplicações modernas baseadas em aprendizado de máquina. Exploramos os desafios que a área necessita enfrentar no momento, tanto de natureza técnica quanto de natureza ética e moral, e concluímos com a inabalável associação do processamento de língua natural com os estudos linguísticos.This is a position paper on the current state of the field of natural language processing (NLP) in Portuguese, its developments from the beginning, and the explosion of recent applications based on machine learning. We explore the challenges that the field is currently facing, of both technical and ethical and moral nature, and conclude with the unwavering association between natural language processing and linguistic studies

Effective prover for minimal inconsistency logic

In this paper we present an e ective prover for mbC, a minimal inconsistency logic. The mbC logic is a paraconsistent logic of the family of logics of formal inconsistency. Paraconsistent logics have several philosophical motivations as well as many applications in Arti cial Intelligence such as in belief revision, inconsistent knowledge reasoning, and logic programming. We have implemented the KEMS prover for mbC, a theorem prover based on the KE tableau method for mbC. We show here that the proof system on which this prover is based is sound, complete and analytic. To evaluate the KEMS prover for mbC, we devised four families of mbC-valid formulas and we present here the rst benchmark results using these families.IFIP International Conference on Artificial Intelligence in Theory and Practice - Expert SystemsRed de Universidades con Carreras en Informática (RedUNCI

Effective prover for minimal inconsistency logic

In this paper we present an e ective prover for mbC, a minimal inconsistency logic. The mbC logic is a paraconsistent logic of the family of logics of formal inconsistency. Paraconsistent logics have several philosophical motivations as well as many applications in Arti cial Intelligence such as in belief revision, inconsistent knowledge reasoning, and logic programming. We have implemented the KEMS prover for mbC, a theorem prover based on the KE tableau method for mbC. We show here that the proof system on which this prover is based is sound, complete and analytic. To evaluate the KEMS prover for mbC, we devised four families of mbC-valid formulas and we present here the rst benchmark results using these families.IFIP International Conference on Artificial Intelligence in Theory and Practice - Expert SystemsRed de Universidades con Carreras en Informática (RedUNCI