When the degree of intersections A∩B of events A,B is unknown arises a problem: how to evaluate the probability P(A ∩ B) and P(A ∩B) from P(A) and P(B). To treat related problems two models of valuation: interval and paired probabilities are proposed. It is shown that the valuation corresponding to the set operations ∩ (intersection), ∪ (union) and ∼ (complement) can be described by the truth f...
