src/HOL/Real/HahnBanach/README.html
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     1 <HTML><HEAD><TITLE>HOL/Real/HahnBanach/README</TITLE></HEAD><BODY>
       
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     3 <H3> The Hahn-Banach theorem for real vectorspaces (Isabelle/Isar).</H3>
       
     4 
       
     5 Author:     Gertrud Bauer, Technische Universit&auml;t M&uuml;nchen<P>
       
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     7 This directory contains the proof of the Hahn-Banach theorem for real vectorspaces,
       
     8 following H. Heuser, Funktionalanalysis, p. 228 -232.
       
     9 The Hahn-Banach theorem is one of the fundamental theorems of functioal analysis.
       
    10 It is a conclusion of Zorn's lemma.<P>
       
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    12 Two different formaulations of the theorem are presented, one for general real vectorspaces
       
    13 and its application to normed vectorspaces. <P>
       
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    15 The theorem says, that every continous linearform, defined on arbitrary subspaces
       
    16 (not only one-dimensional subspaces), can be extended to a continous linearform on
       
    17 the whole vectorspace.
       
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    20 <HR>
       
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    22 <ADDRESS>
       
    23 <A NAME="bauerg@in.tum.de" HREF="mailto:bauerg@in.tum.de">bauerg@in.tum.de</A>
       
    24 </ADDRESS>
       
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    26 </BODY></HTML>
       
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