author wenzelm
Sat, 07 Apr 2012 16:41:59 +0200
changeset 47389 e8552cba702d
parent 36862 952b2b102a0a
permissions -rw-r--r--
explicit checks stable_finished_theory/stable_command allow parallel asynchronous command transactions; tuned;

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<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.


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