Starting from a logic which speci es how to make deductions from a set of sentences (a ` at theory'), a way to generalise this toa partiallyordered bag ofsentences (a `struct...
In this paper we argue that for realistic applications involving default reasoning it is necessary to reason about the priorities of defaults. Existing approaches require the know...
An approach to nonmonotonic inference, based on preference orderings between possible worlds or states of affairs, is presented. We begin with an extant weak theory of default con...
In this paper we continue investigations of proof theory of default logic. It turns out that, similarly to classical logic, default theories can be represented in normal forms.
In this paper we consider supernormal defaults [Poo88] with a strict partial order defining their priorities [Bre91]. We investigate their relation to minimal or preferential ent...