--- a/lex/index.html Wed May 18 11:50:59 2016 +0100
+++ b/lex/index.html Wed May 18 13:45:30 2016 +0100
@@ -33,7 +33,7 @@
in order to deal with POSIX matching, which is the underlying
disambiguation strategy for regular expressions needed in lexers.
Sulzmann and Lu have made available on-line what they call a
-''rigorous proof'' of the correctness of their algorithm w.r.t. their
+``rigorous proof'' of the correctness of their algorithm w.r.t. their
specification; regrettably, it appears to us to have unfillable gaps.
In the first part of this paper we give our inductive definition of
what a POSIX value is and show (i) that such a value is unique (for
@@ -44,27 +44,27 @@
algorithm. Our definitions and proof are much simpler than those by
Sulzmann and Lu and can be easily formalised in Isabelle/HOL. In the
second part we analyse the correctness argument by Sulzmann and Lu and
-explain why it seems hard to turn it into a proof rigorous enough to
-be accepted by a system such as Isabelle/HOL.
+explain why the gaps in this argument cannot be filled easily.
+
<H3>Theory Files for Isabelle 2016</H3>
<ul>
-<li> <A HREF="http://talisker.inf.kcl.ac.uk/%7Eurbanc/cgi-bin/repos.cgi/lexing/raw-file/tip/thys/ReStar.thy">ReStar.thy</A>
+<li> <A HREF="http://talisker.inf.kcl.ac.uk/%7Eurbanc/cgi-bin/repos.cgi/lexing/raw-file/tip/thys/Lexer.thy">ReStar.thy</A>
<li> <A HREF="http://talisker.inf.kcl.ac.uk/%7Eurbanc/cgi-bin/repos.cgi/lexing/raw-file/tip/thys/Simplifying.thy">Simplifying.thy</A>
-<li> <A HREF="http://talisker.inf.kcl.ac.uk/%7Eurbanc/cgi-bin/repos.cgi/lexing/raw-file/tip/thys/Sulzmann.thy">Sulzmann.thy</A>
</ul>
<H3>Links</H3>
<ul>
+<li> <A HREF="http://talisker.inf.kcl.ac.uk/%7Eurbanc/cgi-bin/repos.cgi/lexing/raw-file/tip/thy/paper.pdf">our paper</A>
<li> <A HREF="http://talisker.inf.kcl.ac.uk/%7Eurbanc/cgi-bin/repos.cgi/lexing/raw-file/tip/Literature/sulzmann14-new.pdf">the paper</A> by Sulzmann and Lu
</ul>
</TABLE>
<P>
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