Mechanisms for the automation of uncertainty are required for expert systems. Sometimes
these mechanisms need to obey the properties of probabilistic reasoning. We argue that a
purely numeric mechanism, like those proposed so far, cannot provide a probabilistic logic
with truth functional connectives. We propose an alternative mechanism, Incidence
Calculus, which is based on a representation of uncertainty using sets of points, which might
represent situations models or possible worlds. Incidence Calculus does provide a …

Mechanisms for the automation of uncertainty are required for expert systems. Sometimes
these mechanisms need to obey the properties of probabilistic reasoning. A purely numeric
mechanism, like those proposed so far, cannot provide a probabilistic logic with truth
functional connectives. We propose an alternative mechanism, Incidence Calculus, which is
based on a representation of uncertainty using sets of points, which might represent
situations, models or possible worlds. Incidence Calculus does provide a probabilistic logic …