\documentstyle[12pt,twoside]{article}
\pagestyle{myheadings}
\newtheorem{theorem}{Theorem}
\newtheorem{definition}{Definition}
\newtheorem{proposition}{Proposition}
% \setlength{\oddsidemargin}{0in}
% \setlength{\textwidth}{6.5 in}

%\includeonly{}

\title{Qualitative Simulation of Mechanisms\thanks{This research was
supported in part by the National Library of Medicine through NIH
Grants LM 03603, LM 04125, and R01 LM 04374, and by the National
Science Foundation through grants MCS-8303640 and DCR-8417934.}}

\author{Benjamin Kuipers \\
Clinical Decision Making Group, \\
MIT Laboratory for Computer Science. }

\begin{document}
\maketitle

Abstract:

Qualitative simulation is a key inference process in qualitative
causal reasoning.  However, the precise meaning of the different
proposals and their relation with differential equations is often
unclear.  In this paper, we present a precise definition of
qualitative structure and behavior descriptions as abstractions of
differential equations and continuously differentiable functions.  We
present a new algorithm for qualitative simulation that generalizes
the best features of existing algorithms, and allows direct
comparisons among alternate approaches.  Starting with a structural
description abstracted from a differential equation, we prove that the
QSIM algorithm is guaranteed to produce a qualitative behavior
corresponding to any solution to the original equation.  We also show
that any qualitative simulation algorithm, because of its local point
of view, will sometimes produce spurious qualitative behaviors: ones
which do not correspond to any mechanism satisfying the structural
description.  These observations suggest specific types of care that
must be taken in designing applications of qualitative causal
reasoning systems, and in constructing and validating a knowledge base
of mechanism descriptions.

Keywords:  qualitative simulation, qualitative mathematics, naive physics.
\clearpage
\head{}
\tableofcontents

\include{part1}
\include{part2}
\include{part3}
\appendix
\include{ap1}
\include{ap2}
\include{appdix}

\end{document}
