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...

Abstract For nonmonotonic reasoning in the context of a knowledge base $\mathcal {R}$ R containing conditionals form If A then usually B , system P provides generally accepted axioms. Inference solely based on P, however, is inherently skeptical because it coincides with that takes all ranking models into acc...

In some otherwise attractive formalisms, it can be diicult or even impossible to specify progress in such a way that a component of a distributed system can be proved correct independent of its environment. This problem arises because the nested dependencies between the component and its environment cannot be conveniently expressed in the formalism. A typical example is a communication protocol...

This note is concerned with a formal analysis of the problem of non-monotonic reasoning in intelligent systems, especially when the uncertainty is taken into account in a quantitative way. A firm connection between logic and probability is established by introducing conditioning notions by means of formal structures that do not rely on quantitative measures. The associated conditional logic, co...

In this paper we propose an exception logic { formalizing reasoning about exceptions. We use this logic to defend two claims. First, we argue that default logic { formalizing reasoning about default assumptions { is an extension of exception logic. A deconstruction argument shows that reasoning about exceptions is one of the rst principles of reasoning about default assumptions. Second, we argu...

We present new tractable cases for default reasoning from conditional knowledge bases. In detail, we introduce q-Horn conditional knowledge bases, which allow for a limited use of disjunction. We show that previous tractability results for "-entailment, proper "-entailment, and zand z+-entailment in the Horn case can be extended to the q-Horn case. Moreover, we present feedback-freeHorn conditi...

2 Premise Interpretation in Conditional Reasoning Conditional sentences are pervasive in human communication. Many arguments contain conditional premises or a conditional conclusion. The expression conditional reasoning could appropriately be applied to such arguments. However, there is a tradition in psychological research, which will be followed here, to restrict the use of this expression to...

Children approach counterfactual questions about stories with a reasoning strategy that falls short of adults’ Counterfactual Reasoning (CFR). It was dubbed “Basic Conditional Reasoning” (BCR) in Rafetseder et al. (Child Dev 81(1):376–389, 2010). In this paper we provide a characterisation of the differences between BCR and CFR using a distinction between permanent and nonpermanent features of ...

Ranking theory is a formal epistemology that has been developed in over 600 pages in Spohn's recent book The Laws of Belief, which aims to provide a normative account of the dynamics of beliefs that presents an alternative to current probabilistic approaches. It has long been received in the AI community, but it has not yet found application in experimental psychology. The purpose of this paper...