After arguing that in the knowledge acquisition framework experts cann
ot always supply a precise semantics for the linguistic labels they us
e, we show that negation functions over an ordered set of linguistics
labels induce a semantics. We study the semantics induced by classical
negation, functions from L to L, and also the one induced by negation
functions from L to parts of L. (C) 1996 John Wiley & Sons, Inc.