Mercurial Mercurial > repos > isabelle / file revision
summary | shortlog | changelog | graph | tags | bookmarks | branches | files | changeset | file | latest | revisions | annotate | diff | comparison | raw | help
Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
src/HOL/Real/HahnBanach/README.html
author wenzelm
Mon, 25 Oct 1999 19:24:43 +0200
changeset 7927 b50446a33c16
parent 7655 21b7b0fd41bd
child 15283 f21466450330
permissions -rw-r--r--
update by Gertrud Bauer;

<HTML><HEAD><TITLE>HOL/Real/HahnBanach/README</TITLE></HEAD><BODY>

<H3> The Hahn-Banach Theorem for Real Vector Spaces (Isabelle/Isar).</H3>

Author:     Gertrud Bauer, Technische Universit&auml;t M&uuml;nchen<P>

This directory contains the proof of the Hahn-Banach theorem for real vectorspaces,
following H. Heuser, Funktionalanalysis, p. 228 -232.
The Hahn-Banach theorem is one of the fundamental theorems of functioal analysis.
It is a conclusion of Zorn's lemma.<P>

Two different formaulations of the theorem are presented, one for general real vectorspaces
and its application to normed vectorspaces. <P>

The theorem says, that every continous linearform, defined on arbitrary subspaces
(not only one-dimensional subspaces), can be extended to a continous linearform on
the whole vectorspace.


<HR>

<ADDRESS>
<A NAME="bauerg@in.tum.de" HREF="mailto:bauerg@in.tum.de">bauerg@in.tum.de</A>
</ADDRESS>

</BODY></HTML>
isabelle