Logical Connections of Statements at the Ontological Level

Logical Connections of Statements at the Ontological Level

Cungen Cao (Chinese Academy of Sciences, China), Yuefei Sui (Chinese Academy of Sciences, China) and Yu Sun (Chinese Academy of Sciences, China)
DOI: 10.4018/jcini.2010070105

Abstract

In the classical formal logics, the negation can only be applied to formulas, not to terms and predicates. In (frame-based) knowledge representation, an ontology contains descriptions of individuals, concepts and slots, that is statements about individuals, concepts and slots. The negation can be applied to slots, concepts and statements, so that the logical implication should be considered for all possible combinations of individuals, concepts, slots and statements. In this regard, the logical implication at the ontological level is different from that at the logical level. This paper attempts to give such logical implications between individuals, concepts, slots, statements and their negations.
Article Preview
Top

Introduction

In the first-order logic, there are three logical connectives jcini.2010070105.m01, jcini.2010070105.m02 and negation jcini.2010070105.m03 where jcini.2010070105.m04 can only be applied on formulas to form new formulas, and for any formula jcini.2010070105.m05 and any model jcini.2010070105.m06 is true in jcini.2010070105.m07 if and only if jcini.2010070105.m08 is not true in jcini.2010070105.m09

In natural languages, the connectives and negations have many forms. For example, the exclusive disjunction (exclusive or) and inclusive disjunction (inclusive or). For the negation, the forms are varying. The negation can be applied to a statement (He is not happy), a concept (not a happy man), an individual (Not he is happy) and a value of an attribute (unhappy).

To formalize the different forms of the negation in natural languages, we consider the negation at the ontological level, where the levels are a classification of the various primitives used by knowledge representation systems, firstly defined by Brachman (1979), based on which Guarino (1994) added the ontological level to the levels:

  • jcini.2010070105.m10 The logical level;

  • jcini.2010070105.m11 The epistemological level;

  • jcini.2010070105.m12 The ontological level;

  • jcini.2010070105.m13 The conceptual level, and

  • jcini.2010070105.m14 The linguistic level.

We believe that every level has its own negation.

The negation at the logical level is the logical negation jcini.2010070105.m15 on formulas. In the first order logic, the negation jcini.2010070105.m16 is applied only to formulas, i.e., if jcini.2010070105.m17 is a formula then so is jcini.2010070105.m18; and jcini.2010070105.m19 is false if and only if jcini.2010070105.m20 is true. Hence, jcini.2010070105.m21 and jcini.2010070105.m22 are contradictory.

Complete Article List

Search this Journal:
Reset
Open Access Articles: Forthcoming
Volume 14: 4 Issues (2020): 1 Released, 3 Forthcoming
Volume 13: 4 Issues (2019)
Volume 12: 4 Issues (2018)
Volume 11: 4 Issues (2017)
Volume 10: 4 Issues (2016)
Volume 9: 4 Issues (2015)
Volume 8: 4 Issues (2014)
Volume 7: 4 Issues (2013)
Volume 6: 4 Issues (2012)
Volume 5: 4 Issues (2011)
Volume 4: 4 Issues (2010)
Volume 3: 4 Issues (2009)
Volume 2: 4 Issues (2008)
Volume 1: 4 Issues (2007)
View Complete Journal Contents Listing