Four Characteristic Pieces

Four pieces for modality , context and usage

The main part of this dissertation consists of four loosely connected chapters on the semantics of modals. The chapters inform each other and employ similar methods, but generally each one is self-contained and can be read in isolation. Chapter 2 introduces new semantics for epistemic modality. I argue that the epistemic modal base consists of the propositions that can be obtained by the interl...

Four Easy Pieces: Development Systems for Knowledge-Based Generative Instruction

The Experimental Advanced Design Advisor (XAIDA) is a system for the development of computer-based maintenance training. XAIDA acquires knowledge of a device from a subject matter expert and applies common maintenance-training procedures to generate interactive training from the description. XAIDA provides maintenance training in four areas: the physical characteristics of a device, its theory ...

Klein-Four Covers of the Projective Line in Characteristic Two

In this paper we examine curves defined over a field of characteristic 2 which are (Z/2Z)2-covers of the projective line. In particular, we prove which 2-ranks occur for such curves of a given genus and where possible we give explicit equations for such curves.

Weyl Curvature and the Euler Characteristic in Dimension Four

We give lower bounds, in terms of the Euler characteristic, for the L-norm of the Weyl curvature of closed Riemannian 4-manifolds. The same bounds were obtained by Gursky, in the case of positive scalar curvature metrics.

Two Pieces by Dewey 1 Running head : TWO PIECES BY DEWEY Reflections on Two Pieces