Showing papers by "David Makinson published in 1997"

Applying Normative Rules with Restraint

Abstract: Our purpose is to investigate the logic of applying normative rules. A commonsense distinction may be drawn between applications that are unrestrained, carried through in full even when they give rise to contradiction, and those that are restrained, carried through as fully as is compatible with a principled avoidance of contradictions or of other consequences specified as undesirable. Already, unrestrained application of a normative code is a little more subtle than mere closure under logical consequence. Restrained application in a situation is rather different, we suggest, from revision to accommodate the situation. On the pragmatic level, revision eliminates some normative rules from the code to make consistent place for new material, whereas restrained application leaves all rules intact in the code whilst ignoring some in specific situations. The paper proposes explicit formal definitions of both unrestrained and restrained application of normative rules. For the latter, the most delicate and interesting question is the level at which maximalization-and-choice is most appropriately carried out, in coordination with instantiation and closure under logical consequence.