@MISC{Hughes_started, author = {Jesse Hughes}, title = {Started}, year = {} }

Share

OpenURL

Abstract

project. One of the main aims of this project is the formal-ization of artifactual functions. Artifacts are typically intended for certain uses. A toaster makes toast and a lighter creates small fires. These are the primary functions of toasters and lighters, respectively. We aim to provide a conceptual analysis of such functions via formal semantics. That is, we wish to construct a logical language in which functional ascriptions to artifacts can be expressed and a corresponding semantics which assigns meanings to such statements. We present today the initial steps to this goal. 1.2 Formal semantics for means-end ascrip-tions Functional ascriptions entail related means-end ascriptions. When we say that the function of the toaster is to make toast, we are committed to the claim, “The toaster is a means to producing toast. ” More precisely, we are com-mitted to the claim, “There is some way of using the toaster that will produce toast.” We believe that means-end ascriptions are very closely related to functional ascriptions. Indeed, an analysis of means-end ascriptions is an essential first step to our con-ceptual analysis of functions. We report today on some of the progress on this initial step. We investigate a language in which • ends are formulas, i.e. descriptions of the world; • means are transitions between possible worlds, i.e. ac-tions. 2. The approach 2.1 Dynamic logic An end is a description. A means is some way to change the world so that the end is realized. This strongly suggests that we take dynamic logic as our basic language. Propositional dynamic logic (PDL) [4] is built from a set of atomic propositions and a set of actions. For each action a, we introduce modal operators [a] and 〈a〉. We interpret... as asserting that... [a]ϕ doing a will result in ϕ; 〈a〉ϕ doing a may result in realizing ϕ. The standard semantics for dynamic logic consists of a set of possible worlds together with a non-deterministic labeled transition system. The transition system gives the set of possible outcomes of doing a in a given world.