We will show that Reiter's default logic can be viewed as a particular instantiation of causal reasoning. This will be demonstrated by establishing back and forth translations between default theories and causal theories of the causal calculus under a particular nonmonotonic semantics of causal theories that will be called a default semantics. Moreover, it will be shown that Pearl's structural equation models can be viewed as default causal theories in this sense. We will discuss also some global consequences this representation could have for establishing a general role of causation in nonmonotonic reasoning.

We provide a definition of actual causation in the logical framework of the causal calculus, which is based on a causal version of the well-known NESS (or INUS) condition. We compare our definition with other, mainly counterfactual, approaches on standard examples. On the way, we explore general capabilities of the logical representation for structural equation models of causation and beyond.

We establish a uniform modular translation of Abstract Dialectical Frameworks into the formalism of the causal calculus, and discuss the correspondences this translation creates between a number of semantics suggested for ADFs and their causal counterparts.

We provide a logical representation of Pearl's structural causal models in the causal calculus of McCain and Turner (1997) and its first-order generalization by Lifschitz. It will be shown that, under this representation, the nonmonotonic semantics of the causal calculus describes precisely the solutions of the structural equations (the causal worlds of the causal model), while the causal logic from Bochman (2004) is adequate for describing the behavior of causal models under interventions (forming submodels).

The article provides a uniform representation of abductive reasoning in the logical framework of causal inference relations. The representation covers in a single framework not only traditional, ‘classical’ forms of abduction, but also abductive reasoning in diagnosis, theories of actions and change, and abductive logic programming.

An extension of an abstract argumentation framework is introduced that provides a direct representation of global conflicts between sets of arguments. The extension, called collective argumentation, turns out to be suitable for representing semantics of disjunctive logic programs. Collective argumentation theories are shown to possess a four-valued semantics, and are closely related to multiple-conclusion (Scott) consequence relations. Two special kinds of collective argumentation, positive and negative argumentation, are considered in which the opponents can share their arguments. Negative argumentation turns out to be especially appropriate for analysing stable sets of arguments. Positive argumentation generalizes certain alternative semantics for logic programs.

Abstract A notion of an epistemic state is introduced as a generalization of common representations suggested for belief change. Based on it, a new kind of nonmonotonic inference relation corresponding to belief contractions is defined. A number of representation results is established that cover both traditional AGM contractions and contractions that do not satisfy recovery.

In this paper we develop a logical framework for normal logic programs, called default consequence relations. We give a representation of major semantics for logic programs in this formalism and study the question what logics are adequate for the lat