src/HOL/Real/HahnBanach/document/root.tex
 author wenzelm Thu, 29 Aug 2002 16:08:32 +0200 changeset 13548 36cb5fb8188c parent 11851 d190028f43c5 child 14721 782932b1e931 permissions -rw-r--r--
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\documentclass[10pt,a4paper,twoside]{article}
\usepackage{graphicx}
\usepackage{latexsym,theorem}
\usepackage{isabelle,isabellesym}
\usepackage{pdfsetup} %last one!

\isabellestyle{it}
\urlstyle{rm}

\newcommand{\isasymsup}{\isamath{\sup\,}}
\newcommand{\skp}{\smallskip}

\begin{document}

\pagenumbering{arabic}

\title{The Hahn-Banach Theorem \\ for Real Vector Spaces}
\author{Gertrud Bauer \\ \url{http://www.in.tum.de/~bauerg/}}
\maketitle

\begin{abstract}
The Hahn-Banach Theorem is one of the most fundamental results in functional
analysis. We present a fully formal proof of two versions of the theorem,
one for general linear spaces and another for normed spaces.  This
development is based on simply-typed classical set-theory, as provided by
Isabelle/HOL.
\end{abstract}

\tableofcontents
\parindent 0pt \parskip 0.5ex

\clearpage
\section{Preface}

This is a fully formal proof of the Hahn-Banach Theorem. It closely follows
the informal presentation given in the textbook \cite[{\S} 36]{Heuser:1986}.
Another formal proof of the same theorem has been done in Mizar
\cite{Nowak:1993}.  A general overview of the relevance and history of the
Hahn-Banach Theorem is given in \cite{Narici:1996}.

\medskip The document is structured as follows.  The first part contains
definitions of basic notions of linear algebra: vector spaces, subspaces,
normed spaces, continuous linear-forms, norm of functions and an order on
functions by domain extension.  The second part contains some lemmas about the
supremum (w.r.t.\ the function order) and extension of non-maximal functions.
With these preliminaries, the main proof of the theorem (in its two versions)
is conducted in the third part.  The dependencies of individual theories are
as follows.

\begin{center}
\includegraphics[scale=0.5]{session_graph}
\end{center}

\clearpage
\part {Basic Notions}

\input{Bounds}
\input{Aux}
\input{VectorSpace}
\input{Subspace}
\input{NormedSpace}
\input{Linearform}
\input{FunctionOrder}
\input{FunctionNorm}
\input{ZornLemma}

\clearpage
\part {Lemmas for the Proof}

\input{HahnBanachSupLemmas}
\input{HahnBanachExtLemmas}
\input{HahnBanachLemmas}

\clearpage
\part {The Main Proof}

\input{HahnBanach}
\bibliographystyle{abbrv}
\bibliography{root}

\end{document}