--- a/src/HOL/Algebra/README.html Thu May 01 10:29:44 2003 +0200
+++ b/src/HOL/Algebra/README.html Thu May 01 11:54:18 2003 +0200
@@ -48,6 +48,36 @@
<P>[Ballarin1999] Clemens Ballarin, Computer Algebra and Theorem Proving,
Author's <A HREF="http://iaks-www.ira.uka.de/iaks-calmet/ballarin/publications.html">PhD thesis</A>, 1999.
+<H2>GroupTheory -- Group Theory using Locales, including Sylow's Theorem</H2>
+
+<P>This directory presents proofs about group theory, by
+Florian Kammüller. (Later, Larry Paulson simplified some of the proofs.)
+These theories use locales and were indeed the original motivation for
+locales. However, this treatment of groups must still be regarded as
+experimental. We can expect to see refinements in the future.
+
+Here is an outline of the directory's contents:
+
+<UL> <LI>Theory <A HREF="Group.html"><CODE>Group</CODE></A> defines
+semigroups, groups, homomorphisms and the subgroup relation. It also defines
+the product of two groups. It defines the factorization of a group and shows
+that the factorization a normal subgroup is a group.
+
+<LI>Theory <A HREF="Bij.html"><CODE>Bij</CODE></A>
+defines bijections over sets and operations on them and shows that they
+are a group. It shows that automorphisms form a group.
+
+<LI>Theory <A HREF="Ring.html"><CODE>Ring</CODE></A> defines rings and proves
+a few basic theorems. Ring automorphisms are shown to form a group.
+
+<LI>Theory <A HREF="Sylow.html"><CODE>Sylow</CODE></A>
+contains a proof of the first Sylow theorem.
+
+<LI>Theory <A HREF="Summation.html"><CODE>Summation</CODE></A> Extends
+abelian groups by a summation operator for finite sets (provided by
+Clemens Ballarin).
+</UL>
+
<HR>
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