In this paper, we extend Nilsson's probabilistic logic [1] to allow that each sentence S has three sets of possible worlds. We adopt the ideas of consistency and possible worlds introduced by Nilsson in [1], but propose a new method called linear equation method to deal with the problems of probabilistic inference, the results of our method is consistent with those of Yao's interval-set model method.
['Guilin Qi']
Probabilistic inference on three-valued logic