About Relationships Between two Individuals.

If an internet user wants to access information about two given individuals, he can submit a request with the names of these individuals. However, the occurrences of these two names do not guarantee that the obtained information expresses a relationship between these individuals. The aim of this paper is to propose a clear definition of sentences which express a relationship between two individuals. We first present an informal analysis, based on examples, of this notion of relationship in the context of atomic sentences, or complex sentences which combines logical connectives or quantifiers. In the next section, we give formal definitions, assuming that sentences are expressed in First Order Logic. We define the notion of “path” between individuals, the notion of link between individuals and the notion of relationship between individuals. A Theorem shows how the relationships which are implicitly expressed in complex formulas can be represented in equivalent formulas expressed with “basic relationships”. In the conclusion we suggest possible extensions where the language involves equality, function symbols or modal operators.

Authors

• Robert Demolombe

Keywords

• in the case of