A Formalization of Viewpoints

TitleA Formalization of Viewpoints
Publication TypeTechnical Report
Year of Publication1993
AuthorsAttardi, G., & Simi M.
Other Numbers850
Keywordsbelief and knowledge, contexts, logics for truth, meta-level, situations

We present a formalisation for the notion of "viewpoint," a construct meant for expressing several varieties of relativised truth. The formalisation consists in a logic which extends first order predicate calculus through an axiomatization of provability and with the addition of proper reflection rules. The extension is not conservative, but consistency is granted. Viewpoints are defined as set of reified meta-level sentences. A proof theory for viewponts is developed which enables to carry out proofs of sentences involving several viewpoints. A semantic account of viewpoints is provided, dealing with issues of self referential theories and paradoxes, and exploiting the notion of "contextual entailment." Notions such as beliefs, knowledge, truth and situations can be uniformly modeled as provability in specialised viewpoints, obtained by imposing suitable constraints on viewpoints.

Bibliographic Notes

ICSI Technical Report TR-93-062

Abbreviated Authors

G. Attardi and M. Simi

ICSI Publication Type

Technical Report