--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/index.html~ Wed Mar 30 17:27:34 2016 +0100
@@ -0,0 +1,359 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
+<HEAD>
+<TITLE>Homepage of Christian Urban</TITLE>
+<BASE HREF="http://www.inf.kcl.ac.uk/staff/urbanc/">
+<script type="text/javascript">
+
+ var _gaq = _gaq || [];
+ _gaq.push(['_setAccount', 'UA-4143458-4']);
+ _gaq.push(['_trackPageview']);
+
+ (function() {
+ var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
+ ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
+ var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
+ })();
+
+</script>
+</HEAD>
+
+<BODY TEXT="#000000"
+ BGCOLOR="#4169E1"
+ LINK="#0000EF"
+ VLINK="#51188E"
+ ALINK="#FF0000">
+
+<TABLE WIDTH="100%"
+ BGCOLOR="#4169E1"
+ BORDER="0"
+ FRAME="border"
+ CELLPADDING="10"
+ CELLSPACING="2"
+ RULES="all">
+
+<!-- left column -->
+<TR>
+<TD BGCOLOR="#FFFFFF"
+ WIDTH="24%"
+ VALIGN="TOP"
+ ROWSPAN="9">
+
+<B>Links</B><BR>
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/index.html">Home</A><BR>
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/publications.html">Publications</A><BR>
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/teaching.html">Teaching</A><BR>
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/travelling.html">Recent Talks</A><BR>
+<A HREF="http://isabelle.in.tum.de/nominal/">My Research Group</A>
+<BR>
+<BR>
+
+<B>Handy Information</B><BR>
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/logic.html">People in Logic</A><BR>
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/programming.html">Programming Languages</A><BR>
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/misc.html">Miscellaneous</A>
+<BR><BR>
+
+<table border="0">
+<tr>
+<td>
+<A HREF="http://isabelle.in.tum.de/nominal/">
+<IMG SRC="nominal-logo.gif" ALT="" style="border-width: 0px;" align="left"></A>
+</td>
+</tr>
+<tr>
+<td>
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Cookbook/">
+<IMG SRC="Cookbook/logo-documentation.gif" ALT="" style="border-width: 0px;" align="left"></A>
+</td>
+</tr>
+</table>
+</TD>
+
+
+
+<!-- right column -->
+<TD BGCOLOR="#FFFFFF" WIDTH="75%">
+<A NAME="Home"></A>
+<TABLE>
+<TR>
+<TD WIDTH="75%">
+<H1>Christian Urban</H1>
+
+<B>E-mail</B>
+christian.urban <I>at</I> kcl ac uk<BR>
+<BR>
+
+<B>Address</B>
+<A HREF="http://www.inf.kcl.ac.uk">Department of Informatics</A>,
+<A HREF="http://www.kcl.ac.uk">King's College London</A>,
+Strand, London WC2R 2LS, UK. My office is S1.27 on the 1st floor of the Strand Building.
+<BR>
+
+</TD>
+<TD align="right" valign="top">
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/picture-small.jpg"><IMG ALT="" SRC="picture-small.jpg" align="top"></A>
+</TD>
+</TR>
+</TABLE>
+<p>
+<IMG SRC="new.gif" ALT="" style="" align="left"><A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Cookbook" target="_top">Isabelle Programming Tutorial</A> (draft of a 200-page tutorial on Isabelle programming)<BR><BR>
+</TD>
+</TR>
+
+<TR>
+<TD BGCOLOR="#FFFFFF" WIDTH="75%">
+<B>Current Position</B>
+I am a lecturer in the Department of Informatics at King's College London.
+This is similar to a position of an assistant professor in other places. In 2011,
+I was also offered a lectureship
+<A HREF="http://www.it.uu.se/" TITLE="Uppsala">here</A>, an associate professorship
+<A HREF="http://www.itu.dk/en/" TITLE="ITU, Copenhagen">here</A>,
+and full professorships
+<A HREF="http://www.ustcsz.edu.cn/kedweb/" TITLE="IAS, Suzhou">here</A> and
+<A HREF="http://202.120.81.220/index.aspx" TITLE="Shanghai">here</A>.
+I thank all people involved for their efforts.
+<P>
+
+<B>Past Positions</B>
+In April 2006, I was awarded an <A HREF="http://en.wikipedia.org/wiki/Emmy_Noether">Emmy-Noether</A>
+<A HREF="http://www.dfg.de/en/research_funding/programmes/individual/emmy_noether/in_brief/index.html">fellowship</A>, which I held at the <A HREF="http://www.in.tum.de/en.html">TU Munich</A> until
+September 2011.
+Between September 2008 and February 2009, I was an invited research scientist in
+the <A HREF="http://www.cs.princeton.edu/">Department of Computer Science</A> in Princeton.
+In 2004/05 I was an Alexander-von-Humboldt fellow in Munich and
+from 2000 until 2004 I was awarded a Research Fellowship in Cambridge. Before that
+I did my PhD in Cambridge funded by two scholarships from the German Academic Exchange
+Service (<A HREF="http://www.daad.de/index.html">DAAD</A>).
+<P>
+
+<B>Skolem Award 2015</B> Together with
+<A HREF="http://www.pps.univ-paris-diderot.fr/~tasson/">Christine Tasson</A>, I was awarded a
+<A HREF="http://www.cadeinc.org/SkolemAward.html">Thoralf Skolem Award</A>, a ten-year
+ test-of-time award from CADE, for our
+ <A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Publications/nom-cade-05.ps">paper</A>
+ on Nominal Techniques in Isabelle/HOL from 2005.
+<P>
+
+<B>Research Interests</B> theorem provers, verification, programming languages, compilers,
+algorithms, proof theory, type systems, concurrency, lambda calculus, unification,
+regular expressions, computability, complexity, functional and logic programming.
+<P>
+
+<B>Teaching</B> I usually enjoy teaching. At King's my students nominated me for the Teaching
+Excellence Award in
+2012 and 2015, and for the best MSc Project supervisor in 2015.
+In 2014 I received both prizes for Best UG Project Supervisor and for Best
+MSc Project Supervisor in the <A HREF="http://www.kcl.ac.uk/nms/index.aspx">NMS Faculty<A>.<P>
+
+
+<B>Conferences</B>
+UNIF'06 (member of PC),
+<A HREF="http://www.cs.mcgill.ca/~bpientka/lfmtp07">LFMTP'07</A> (member of PC),
+<A HREF="http://isabelle.in.tum.de/nominal/activities/lfmtp08/">LFMTP'08</A> (PC co-chair),
+<A HREF="http://www.cis.upenn.edu/~sweirich/wmm/">WMM'08</A> (member of PC),
+<A HREF="http://www.mat.ufmg.br/lsfa2008/">LSFA'08</A> (invited speaker),
+<A HREF="http://www.inf.kcl.ac.uk/staff/maribel/TAASN.html">TAASN'09</A> (member of PC),
+<A HREF="http://lsfa09.cic.unb.br/">LSFA'09</A> (member of PC),
+<A HREF="http://isabelle.in.tum.de/nominal/activities/tphols09/idw.html">IDW'09</A> (organiser),
+<A HREF="http://www.seas.upenn.edu/~sweirich/wmm/wmm09.html">WMM'09</A> (PC chair),
+<A HREF="https://isabelle.in.tum.de/nominal/activities/tphols09/">TPHOLs'09</A> (PC co-chair),
+<A HREF="http://dream.inf.ed.ac.uk/events/automatheo-2010/">Automatheo'10</A> (member of PC),
+<A HREF="http://www.floc-conference.org/">ITP'10</A> (member of PC),
+<A HREF="http://www.inf.kcl.ac.uk/staff/maribel/UNIF/UNIF.html">UNIF'10</A> (invited speaker),
+<A HREF="http://www.cis.upenn.edu/~bcpierce/wmm/">WMM'10</A> (invited speaker),
+<A HREF="http://isabelle.in.tum.de/nominal/activities/idw10/idw.html">IDW'10</A> (co-organiser),
+CPP'11 (member of PC),
+<A HREF="http://www.rdp2011.uns.ac.rs/rta/">RTA'11</A> (member of PC),
+<A HREF="http://lfmtp11.cs.umn.edu">LFMTP'11</A> (member of PC),
+<A HREF="http://www.cs.uwyo.edu/~ruben/itp-2014">ITP'14</A> (member of PC),
+<A HREF="http://www.cicm-conference.org/2015/cicm.php?event=mkm">MKM'15</A> (member of PC),
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/itp-2015/">ITP'15</A> (PC co-chair)
+<P>
+
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/itp-2015/">ITP'15</A> took place in Nanjing organised
+by Xingyuan Zhang and me<BR>
+<p>
+
+<B>Current PhD</B> Fahad Ausaf<BR>
+<B>Former RAs</B> Chunhan Wu, <A HREF="http://cl-informatik.uibk.ac.at/users/cek/">Cezary Kaliszyk</A>,
+<A HREF="http://dpt-info.u-strasbg.fr/~narboux/">Julien Narboux</A>
+</TD>
+</TR>
+
+<TR>
+<TD BGCOLOR="#FFFFFF" WIDTH="75%">
+<B>Nominal Isabelle</B>
+I currently work on Nominal
+<A HREF="http://isabelle.in.tum.de">Isabelle</A> 2. This is joint work with
+<A HREF="http://wwwbroy.in.tum.de/~berghofe/">Dr Stefan Berghofer</A>,
+<A HREF="http://www.lri.fr/~wenzel/">Dr Markus Wenzel</A>,
+<A HREF="http://cl-informatik.uibk.ac.at/users/cek/">Dr Cezary Kaliszyk</A>,
+<A HREF="http://user.it.uu.se/~tjawe125/">Dr Tjark Weber</A> and
+the Isabelle-team in Munich.
+Many of the theoretical ideas originate from the nominal logic project - a wonderful project headed
+by <A HREF="http://www.cl.cam.ac.uk/~amp12/">Prof. Andrew Pitts</A>.
+The aim of my work is to make formal reasoning involving binders as simple as
+on paper and the hope is to lure
+<A HREF="http://alliance.seas.upenn.edu/~plclub/cgi-bin/poplmark/index.php?title=The_POPLmark_Challenge#Vision">masses</A> to automated
+theorem proving. My funding for this work was provided in 2004 and 2005 by a research
+fellowship from the
+<A HREF="http://en.wikipedia.org/wiki/Alexander_von_Humboldt">Alexander-von-Humboldt</A>
+<A HREF="http://www.humboldt-foundation.de/web/home.html">foundation</A>. During this time I was a visitor in the group of
+<A HREF="http://www.mathematik.uni-muenchen.de/~schwicht/">Prof. Helmut Schwichtenberg</A>.
+Since 2006 this work is supported by an
+<A HREF="http://en.wikipedia.org/wiki/Emmy_Noether">Emmy-Noether</A>
+<A HREF="http://www.dfg.de/en/research_funding/programmes/individual/emmy_noether/in_brief/index.html">fellowship</A>.
+There is a <A HREF="http://isabelle.in.tum.de/nominal/">webpage</A> and a
+<A HREF="https://mailmanbroy.informatik.tu-muenchen.de/mailman/listinfo/nominal-isabelle">mailing list</A>
+about Nominal Isabelle. It also includes a list of projects that use Nominal Isabelle.
+Users of Nominal Isabelle had their papers appearing at LICS, POPL, FOSSACS, SOS, TPHOLs, CPP, SEFM,
+the Haskell Symposium and
+in the Journal of Automated Reasoning.
+</TD>
+</TR>
+
+<TR>
+<TD BGCOLOR="#FFFFFF" WIDTH="75%">
+<B>Myhill-Nerode and Regular Expressions</B>
+Out of frustration of having to teach reasoning in theorem provers with worn-out examples like
+fib and even/odd, we implemented a large part of regular language theory in Isabelle/HOL.
+This <A HREF="http://afp.sourceforge.net/devel-entries/Myhill-Nerode.shtml">implementation</A>
+gives rise to much more interesting examples, as shown
+<A HREF="http://www.cs.cmu.edu/~rwh/papers/regexp/jfp.pdf">here</A> and
+<A HREF="http://ropas.snu.ac.kr/~kwang/paper/06-jfp-yi.pdf">here</A>. It turns out that
+formalisations of automata theory are a huge
+<A HREF="https://lists.cam.ac.uk/pipermail/cl-isabelle-users/2005-September/msg00012.html">pain</A>
+in theorem provers, especially in those that are based on HOL.
+We therefore went against the
+<A HREF="http://www.cs.cornell.edu/~kozen/papers/papers_by_year.htm#K97a">mainstream</A>
+and used in our formalisation regular expressions exclusively,
+because they are much more convenient for formal reasoning. The results we
+formalised include: the Myhill-Nerode theorem, the closure of regular languages
+under complementation, finiteness of derivatives of regular expressions and a surprising
+result about Subseq, which according to
+this
+<A HREF="http://blog.computationalcomplexity.org/2006/01/theorem-that-should-be-better-known.html">blog</A>
+should be better known. We also answered a
+<A HREF="http://blog.computationalcomplexity.org/2013/02/proving-dfa-langs-closed-under-concat.html">question</A> from the same blog about
+"proving Reg-exp-langs [being] closed under complementation without using equiv to DFA's"....yes we can!
+This is joint work with Prof. Xingyuan
+Zhang and his student Chunhan Wu from the
+<A HREF="http://www.ust.com.cn/">PLA University of Science and Technology</A> in Nanjing.
+My funding for this work came from the
+<A HREF="http://www.sinogermanscience.org.cn/">Chinese-German Research Centre</A>.
+</TD>
+</TR>
+
+<!--
+<TR>
+<TD BGCOLOR="#FFFFFF" WIDTH="75%">
+<B>Priority Inheritance</B>
+ In real-time operating systems with processes, resource locking and
+ priority scheduling, one faces the problem of indefinite
+ <A HREF="http://en.wikipedia.org/wiki/Priority_inversion">priority inversion</A> (processes
+ with lower priority block processes with higher priority). If you do not prevent this problem,
+ then processes can behave quite erratically, as <A HREF="http://www.nasa.gov">NASA</A> found out the
+ <A HREF="http://catless.ncl.ac.uk/Risks/19.54.html#subj6">hard</A> way with their
+ <A HREF="http://www.nasa.gov/mission_pages/mars-pathfinder/index.html">Mars Pathfinder mission</A>.
+ The priority inheritance protocol is a widely used schedulling algorithm that prevents
+ priority inversion. However, the <A HREF="http://dx.doi.org/10.1109/12.57058">original paper</A>
+ describing this algorithm contains an incorrect algorithm and a bogus correctness proof
+ (this seems to be the only "proof" about priority inheritance in the literature).
+
+ We formalised the priority inheritance protocol, including a generalisation
+ of the original work.
+
+ using the inductive method we learned from
+ <A HREF="https://www.cl.cam.ac.uk/~lp15/">Prof. Larry Paulson</A>.
+ While the problem with the original algorithm was already known, the incorrect
+ specification seems to be still in use
+
+ <A HREF="http://mcs.une.edu.au/%7Eiam/Data/threads/node15.html">here</A>
+ <A HREF="http://ems2.be/Portals/6/course_docs/OS_pathfinder_failure.ppt">
+
+ This is joint work with Prof. Xingyuan Zhang and his student Chunhan Wu from the
+ <A HREF="http://www.ust.com.cn/">PLA University of Science and Technology</A> in Nanjing.
+</TD>
+</TR>
+-->
+
+<TR>
+<TD BGCOLOR="#FFFFFF" WIDTH="75%">
+<B>Nominal Unification and Alpha-Prolog</B>
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Unification">Nominal unification</A> is one outcome of
+my involvement in the nominal logic project in Cambridge. Another is the logic programming language
+alpha-Prolog (joint work with <A HREF="http://homepages.inf.ed.ac.uk/jcheney/">Dr James Cheney</A>),
+which uses nominal unification - click for details
+<A HREF="http://homepages.inf.ed.ac.uk/jcheney/programs/aprolog/">here</A>.
+The nominal unification algorithm has been
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Unification">formally verified</A> in Isabelle. This
+was possible since this unification algorithm is formulated in a simple first-order language
+(unlike other algorithms for higher-order unification).
+<A HREF="http://www.cs.indiana.edu/~dfried/">Prof. Daniel Friedman</A> and his group use nominal
+unification in their alpha-Kanren system implemented in Scheme.
+<A HREF="http://www.inf.kcl.ac.uk/staff/maribel/">Prof. Maribel Fernandez</A> and her student
+improved the nominal unification algorithm to be quadratic.
+My funding for this work was provided through a research fellowship from
+<A HREF="http://www.corpus.cam.ac.uk">Corpus Christi College</A>, Cambridge.
+</TD>
+</TR>
+
+<TR>
+<TD BGCOLOR="#FFFFFF" WIDTH="75%">
+<B>Classical Logic</B>
+I was Ph.D. student in the University of Cambridge
+<A HREF="http://www.cl.cam.ac.uk">Computer Laboratory</A>
+and for three years
+called Gonville and Caius College my home. I was very lucky to have
+<A HREF="https://labs.oracle.com/pls/apex/f?p=labs:bio:0:2044">Dr Gavin Bierman</A>
+as supervisor. My research in Cambridge was also very much influenced by
+<A HREF="http://www.dpmms.cam.ac.uk/~martin/">Prof. Martin Hyland</A>.
+Some details on my thesis "Classical Logic and Computation" are
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/PhD/index.html">elsewhere</A>, including
+a <A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Cut/cutapplet.html">Java Applet</A> that
+'visualises' some of the results from the thesis. I completed the writing of
+the thesis in <A HREF="http://iml.univ-mrs.fr/ldp/">Marseille</A> in the group of
+<A HREF="http://iml.univ-mrs.fr/~girard/">Prof. Jean-Yves Girard</A>. My study in
+Cambridge was funded by two <A HREF="http://www.daad.de/index.html">scholarships</a>
+from the German government; my year in Marseille by a TMR-fellowship from the EU.
+My PhD was also one starting point for the EPSRC Project on the Semantics of Classical
+Proofs. The strong normalisation result in the PhD has been used in 2007 by
+<A HREF="http://www.loria.fr/~ckirchne/hot.html">Prof. Claude Kirchner</A> and his
+students for proving consistency of their superdeduction system lemuridae.
+</TD>
+</TR>
+
+
+
+<TR>
+<TD BGCOLOR="#FFFFFF" WIDTH="75%">
+<B>Forum</B>
+I implemented Forum, a programming language based on classical linear logic,
+as my M.Phil. thesis. This was joint work with
+<A HREF="http://www.cs.st-andrews.ac.uk/~rd/">Dr Roy Dyckhoff</A>.
+Details can be found
+<A HREF="http://www.cs.st-andrews.ac.uk/~rd/logic/nonmac/">here</A> and
+<A HREF="http://www.lix.polytechnique.fr/Labo/Dale.Miller/forum/">here</A>. During my
+M.Phil study I spent one month in Philadelphia invited by
+<A HREF="http://www.lix.polytechnique.fr/~dale/">Prof. Dale Miller</A>.
+</TD>
+</TR>
+
+<TR>
+<TD BGCOLOR="#FFFFFF" WIDTH="75%">
+<B>G4ip</B> An implementation of G4ip using the imperative language Pizza can be found
+<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Prover/index.html">here</A>.
+<A HREF="http://pizzacompiler.sourceforge.net">Pizza</A>, written around 1996, is a conservative
+extension of Java and a precursor of Scala. My implementation illustrates the technique of
+success continuations in proof search.
+</TD>
+</TR>
+
+
+</TABLE>
+<P>
+<!-- hhmts start --> Last modified: Fri Nov 13 13:13:26 GMT 2015 <!-- hhmts end -->
+<a href="http://validator.w3.org/check/referer">[Validate this page.]</a>
+</BODY>
+</HTML>