A Semantics for Functional Efficacy

Artifactual functions are related to means-end relations. Whatever else a functional ascription conveys, it expresses the expectation that artifacts of the appropriate type may be used to achieve the functional goal. We use our existing work on means-end semantics to make this relationship precise and present a preliminary formal account of artifactual functions. We adapt our work on probabilistic transition systems and fuzzy dynamic logic to add a measure of efficacy to both our means-end semantics and definition of function-fulfillment. Efficacy allows a rudimentary definition of one kind of malfunction, namely, a token which has much lower efficacy in achieving its functional goal than normal tokens of that type is malfunctioning. “A whistle is to make people jump.” Ruth Krauss, A Hole is to Dig