Intensions as Such: An Outline

Abstract

The formal expression of propositional attitudes, especially when n este d (iterated), is an important problem for AI. An inter esti ng first-order extensional logical syst em for such exp ressi on has been proposed by Creary . In this system concepts (and concepts of concepts, etc.) are made explicit. The system includes "concept functions ", which are special functions which act on and deliver concepts. We point out a difficulty with these functions. A alternative system is proposed, in which there is a concept,. forming function corresponding roughly to complexconcept formers (especially the phrase "the proposition that") implicit in English sentences. The resulting system has a more primitive and natural notional base than Creary's has. We avoid problems with quantification inside propositions which are the objects of propositional attitudes by recasting quantified expressions into variable-free form by means of certain functions ("com binators " ).