COMBINING FUNCTIONS FOR CERTAINTY DEGREES IN CONSULTING SYSTEMS

Consulting systems are rule-based systems of Artificial Intelligence working with propositions that may be uncertain, i. e. may have a truth-value different from 'true' and 'false'. The work of a consulting system consists, roughly, in propagation of uncertain knowledge throughout the net of rules according to some combining functions. It is shown that the notion of an ordered Abelian group is central for the definition of these combining functions. Various particular groups, both Archimedean and non-Archimedean, are considered for use in consulting systems. Practical experiments with them are also described.