A rational agent changes her beliefs in response to new information; a widely held idea is that such belief changes should be minimal. This paper is an overview of the theory of minimal belief revision. I employ a decisiontheoretic framework to compare various principles for minimal belief revision. The main topics covered include the AGM postulates for belief revision, belief contraction, Grov...

anonymous referee for the Journal of Philosophical Logic for their insightful comments on earlier versions of this paper. I also thank Prasanta Bandy-opadhyay, Jim Cain, Francis Jeery Pelletier and Ted Sider for their sugges tions and encouragement, and acknowledge the help of my friend Ramkrish-nan Nambimadom in the construction of a crucial proof. Abstract: This paper is concerned with the co...

geometry. !& 1993 Academic Press, lnc. ing and inflammation, then a rational basis for the design and application ofpharmacologic modulators of cell behavior to augment or mitigate wound contraction (as appropriate for the nature of the wound being managed) would be available. The model proposed here is a first attempt in that direction. A preponderance of evidence implicates fibroblastic cells...

A polynomial map f : C2 → C is rational if its generic fibre, and hence every fibre, is of genus zero. It is of simple type if, when extended to a morphism f̃ : X → P1 of a compactification X of C2, the restriction of f̃ to each curve C of the compactification divisor D = X − C2 is either degree 0 or 1. The curves C on which f̃ is non-constant are called horizontal curves, so one says briefly “eac...

In many database applications, designers can easily provide at least some information about the relative importance of the information to be stored and manipulated. While of potentially high value, the ordering information is typically only partial. Here we address the issue of updates in such partially ordered situations, which we call epistemically stratiied databases. In the current database...

We study ruled orders. These arise naturally in the Mori program for orders on projective surfaces and morally speaking are orders on a ruled surface ramified on a bisection and possibly some fibres. We describe fibres of a ruled order and show they are in some sense rational. We also determine the Hilbert scheme of rational curves and hence the corresponding non-commutative Mori contraction. T...