Coherent T-conditional Possibility Envelopes and Nonmonotonic Reasoning
نویسندگان
چکیده
Envelopes of coherent T -conditional possibilities and coherent T -conditional necessities are studied and an analysis of some inference rules which play an important role in nonmonotonic reasoning is
منابع مشابه
Is Human Reasoning about Nonmonotonic Conditionals Probabilistically Coherent?
Nonmonotonic conditionals (A |∼ B) are formalizations of common sense expressions of the form “if A, normally B”. The nonmonotonic conditional is interpreted by a “high” coherent conditional probability, P (B|A) > .5. Two important properties are closely related to the nonmonotonic conditional: First, A |∼ B allows for exceptions. Second, the rules of the nonmonotonic system p guiding A |∼ B al...
متن کاملEnvelopes of conditional probabilities extending a strategy and a prior probability
Any strategy and prior probability together are a coherent conditional probability that can be extended, generally not in a unique way, to a full conditional probability. The corresponding class of extensions is studied and a closed form expression for its envelopes is provided. Then a topological characterization of the subclasses of extensions satisfying the further properties of full disinte...
متن کاملNonmonotonic Reasoning, Conditional Objects and Possibility Theory
This short paper relates the conditional object-based and possibility theorybased approaches for reasoning with conditional statements pervaded with exceptions, to other methods in nonmonotonic reasoning which have been independently proposed: namely, Lehmann's preferential and rational closure entailments which obey normative postulates, the infinitesimal probability approach, and the conditio...
متن کاملMarginal extension in the theory of coherent lower previsions
We generalise Walley’s Marginal Extension Theorem to the case of any finite number of conditional lower previsions. Unlike the procedure of natural extension, our marginal extension always provides the smallest (most conservative) coherent extensions. We show that they can also be calculated as lower envelopes of marginal extensions of conditional linear (precise) previsions. Finally, we use ou...
متن کاملCoherence of rules for defining conditional possibility
Possibility measures and conditional possibility measures are given a behavioural interpretation as marginal betting rates against events. Under this interpretation, possibility measures should satisfy two consistency criteria, known as ‘avoiding sure loss’ and ‘coherence’. We survey the rules that have been proposed for defining conditional possibilities and investigate which of them satisfy o...
متن کامل