|
2
|
1 |
<?xml version="1.0" encoding="utf-8"?>
|
|
|
2 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
|
|
3 |
<HEAD>
|
|
|
4 |
<TITLE>Homepage of Christian Urban</TITLE>
|
|
24
|
5 |
<BASE HREF="http://www.inf.kcl.ac.uk/staff/urbanc/">
|
|
23
|
6 |
<script type="text/javascript">
|
|
|
7 |
|
|
|
8 |
var _gaq = _gaq || [];
|
|
|
9 |
_gaq.push(['_setAccount', 'UA-4143458-4']);
|
|
|
10 |
_gaq.push(['_trackPageview']);
|
|
|
11 |
|
|
|
12 |
(function() {
|
|
|
13 |
var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
|
|
|
14 |
ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
|
|
|
15 |
var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
|
|
|
16 |
})();
|
|
|
17 |
|
|
|
18 |
</script>
|
|
2
|
19 |
</HEAD>
|
|
|
20 |
|
|
|
21 |
<BODY TEXT="#000000"
|
|
|
22 |
BGCOLOR="#4169E1"
|
|
|
23 |
LINK="#0000EF"
|
|
|
24 |
VLINK="#51188E"
|
|
|
25 |
ALINK="#FF0000">
|
|
|
26 |
|
|
|
27 |
<TABLE WIDTH="100%"
|
|
|
28 |
BGCOLOR="#4169E1"
|
|
|
29 |
BORDER="0"
|
|
|
30 |
FRAME="border"
|
|
|
31 |
CELLPADDING="10"
|
|
|
32 |
CELLSPACING="2"
|
|
|
33 |
RULES="all">
|
|
|
34 |
|
|
|
35 |
<!-- left column -->
|
|
|
36 |
<TR>
|
|
|
37 |
<TD BGCOLOR="#FFFFFF"
|
|
|
38 |
WIDTH="24%"
|
|
|
39 |
VALIGN="TOP"
|
|
|
40 |
ROWSPAN="8">
|
|
|
41 |
|
|
|
42 |
<B>Links</B><BR>
|
|
24
|
43 |
<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/index.html">Home</A><BR>
|
|
|
44 |
<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/publications.html">Publications</A><BR>
|
|
|
45 |
<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/teaching.html">Teaching</A><BR>
|
|
|
46 |
<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/travelling.html">Recent Talks</A><BR>
|
|
2
|
47 |
<A HREF="http://isabelle.in.tum.de/nominal/">My Research Group</A>
|
|
|
48 |
<BR>
|
|
|
49 |
<BR>
|
|
|
50 |
|
|
|
51 |
<B>Handy Information</B><BR>
|
|
24
|
52 |
<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/logic.html">People in Logic</A><BR>
|
|
|
53 |
<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/programming.html">Programming Languages</A><BR>
|
|
|
54 |
<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/misc.html">Miscellaneous</A>
|
|
2
|
55 |
<BR><BR>
|
|
|
56 |
|
|
37
|
57 |
<table border="0">
|
|
|
58 |
<tr>
|
|
|
59 |
<td>
|
|
2
|
60 |
<A HREF="http://isabelle.in.tum.de/nominal/">
|
|
5
|
61 |
<IMG SRC="nominal-logo.gif" ALT="" style="border-width: 0px;" align="left"></A>
|
|
37
|
62 |
</td>
|
|
|
63 |
</tr>
|
|
|
64 |
<tr>
|
|
|
65 |
<td>
|
|
|
66 |
<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Cookbook/">
|
|
|
67 |
<IMG SRC="Cookbook/logo-documentation.gif" ALT="" style="border-width: 0px;" align="left"></A>
|
|
|
68 |
</td>
|
|
|
69 |
</tr>
|
|
|
70 |
</table>
|
|
2
|
71 |
</TD>
|
|
|
72 |
|
|
|
73 |
|
|
|
74 |
|
|
|
75 |
<!-- right column -->
|
|
|
76 |
<TD BGCOLOR="#FFFFFF" WIDTH="75%">
|
|
|
77 |
<A NAME="Home"></A>
|
|
|
78 |
<TABLE>
|
|
|
79 |
<TR>
|
|
|
80 |
<TD WIDTH="75%">
|
|
16
|
81 |
<H1>Christian Urban</H1>
|
|
2
|
82 |
|
|
|
83 |
<B>E-mail</B>
|
|
22
|
84 |
christian.urban <I>at</I> kcl ac uk<BR>
|
|
2
|
85 |
<BR>
|
|
|
86 |
|
|
|
87 |
<B>Address</B>
|
|
24
|
88 |
<A HREF="http://www.inf.kcl.ac.uk">Department of Informatics</A>,
|
|
16
|
89 |
<A HREF="http://www.kcl.ac.uk">King's College London</A>,
|
|
|
90 |
Strand, London WC2R 2LS, UK. My office is S6.30 on the 6th floor of the Strand Building.
|
|
2
|
91 |
<BR><BR>
|
|
|
92 |
|
|
16
|
93 |
<B>Fax</B> +44 20 7848 2851
|
|
2
|
94 |
</TD>
|
|
|
95 |
<TD align="right" valign="top">
|
|
24
|
96 |
<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/picture-small.jpg"><IMG ALT="" SRC="picture-small.jpg" align="top"></A>
|
|
2
|
97 |
</TD>
|
|
|
98 |
</TR>
|
|
|
99 |
</TABLE>
|
|
|
100 |
<p>
|
|
36
|
101 |
<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>
|
|
2
|
102 |
</TD>
|
|
|
103 |
</TR>
|
|
|
104 |
|
|
|
105 |
<TR>
|
|
|
106 |
<TD BGCOLOR="#FFFFFF" WIDTH="75%">
|
|
|
107 |
<B>Current Position</B>
|
|
17
|
108 |
I am a lecturer in the Department of Informatics at King's College London.
|
|
21
|
109 |
This is similar to a position of an assistant professor in other places. In 2011,
|
|
17
|
110 |
I was also offered a lectureship
|
|
|
111 |
<A HREF="http://www.it.uu.se/" TITLE="Uppsala">here</A>, an associate professorship
|
|
|
112 |
<A HREF="http://www.itu.dk/en/" TITLE="ITU, Copenhagen">here</A>,
|
|
21
|
113 |
and full professorships
|
|
17
|
114 |
<A HREF="http://www.ustcsz.edu.cn/kedweb/" TITLE="IAS, Suzhou">here</A> and
|
|
|
115 |
<A HREF="http://www.sei.ecnu.edu.cn/apps/portal/home.html" TITLE="Shanghai">here</A>.
|
|
|
116 |
I thank all people involved for their efforts.
|
|
2
|
117 |
<P>
|
|
|
118 |
|
|
|
119 |
<B>Past Positions</B>
|
|
17
|
120 |
In April 2006, I was awarded an <A HREF="http://en.wikipedia.org/wiki/Emmy_Noether">Emmy-Noether</A>
|
|
|
121 |
<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
|
|
|
122 |
September 2011.
|
|
56
|
123 |
Between September 2008 and February 2009, I was an invited research scientist in
|
|
2
|
124 |
the <A HREF="http://www.cs.princeton.edu/">Department of Computer Science</A> in Princeton.
|
|
|
125 |
In 2004/05 I was an Alexander-von-Humboldt fellow in Munich and
|
|
|
126 |
from 2000 until 2004 I was awarded a Research Fellowship in Cambridge. Before that
|
|
46
|
127 |
I did my PhD in Cambridge funded by two scholarships from the German Academic Exchange
|
|
45
|
128 |
Service (<A HREF="http://www.daad.de/index.html">DAAD</A>).
|
|
2
|
129 |
<P>
|
|
|
130 |
|
|
62
|
131 |
<B>Research Interests</B> theorem provers, verification, programming languages, compilers,
|
|
2
|
132 |
algorithms, proof theory, type systems, concurrency, lambda calculus, unification,
|
|
|
133 |
regular expressions, computability, complexity, functional and logic programming.
|
|
|
134 |
<P>
|
|
|
135 |
|
|
|
136 |
<B>Conferences</B>
|
|
|
137 |
<A HREF="http://www.iiia.csic.es/~levy/unif06/">UNIF'06</A> (member of PC),
|
|
|
138 |
<A HREF="http://www.cs.mcgill.ca/~bpientka/lfmtp07">LFMTP'07</A> (member of PC),
|
|
|
139 |
<A HREF="http://isabelle.in.tum.de/nominal/activities/lfmtp08/">LFMTP'08</A> (PC co-chair),
|
|
|
140 |
<A HREF="http://www.cis.upenn.edu/~sweirich/wmm/">WMM'08</A> (member of PC),
|
|
|
141 |
<A HREF="http://www.mat.ufmg.br/lsfa2008/">LSFA'08</A> (invited speaker),
|
|
24
|
142 |
<A HREF="http://www.inf.kcl.ac.uk/staff/maribel/TAASN.html">TAASN'09</A> (member of PC),
|
|
2
|
143 |
<A HREF="http://lsfa09.cic.unb.br/">LSFA'09</A> (member of PC),
|
|
|
144 |
<A HREF="http://isabelle.in.tum.de/nominal/activities/tphols09/idw.html">IDW'09</A> (organiser),
|
|
|
145 |
<A HREF="http://www.seas.upenn.edu/~sweirich/wmm/wmm09.html">WMM'09</A> (PC chair),
|
|
|
146 |
<A HREF="http://tphols.in.tum.de/">TPHOLs'09</A> (PC co-chair),
|
|
|
147 |
<A HREF="http://dream.inf.ed.ac.uk/events/automatheo-2010/">Automatheo'10</A> (member of PC),
|
|
|
148 |
<A HREF="http://www.floc-conference.org/">ITP'10</A> (member of PC),
|
|
24
|
149 |
<A HREF="http://www.inf.kcl.ac.uk/staff/maribel/UNIF.html">UNIF'10</A> (invited speaker),
|
|
2
|
150 |
<A HREF="http://www.cis.upenn.edu/~bcpierce/wmm/">WMM'10</A> (invited speaker),
|
|
|
151 |
<A HREF="http://isabelle.in.tum.de/nominal/activities/idw10/idw.html">IDW'10</A> (co-organiser),
|
|
|
152 |
<A HREF="http://formes.asia/cpp">CPP'11</A> (member of PC),
|
|
|
153 |
<A HREF="http://www.rdp2011.uns.ac.rs/rta/">RTA'11</A> (member of PC),
|
|
|
154 |
<A HREF="http://lfmtp11.cs.umn.edu">LFMTP'11</A> (member of PC)
|
|
|
155 |
<BR>
|
|
|
156 |
|
|
|
157 |
</TD>
|
|
|
158 |
</TR>
|
|
|
159 |
|
|
|
160 |
<TR>
|
|
|
161 |
<TD BGCOLOR="#FFFFFF" WIDTH="75%">
|
|
|
162 |
<B>Nominal Isabelle</B>
|
|
|
163 |
I currently work on Nominal
|
|
|
164 |
<A HREF="http://isabelle.in.tum.de">Isabelle</A>. This is joint work with
|
|
|
165 |
<A HREF="http://wwwbroy.in.tum.de/~berghofe/">Dr Stefan Berghofer</A>,
|
|
|
166 |
<A HREF="http://www4.in.tum.de/~wenzelm/">Dr Markus Wenzel</A>,
|
|
|
167 |
<A HREF="http://www4.in.tum.de/~kaliszyk/">Dr Cezary Kaliszyk</A> and
|
|
|
168 |
the Isabelle-team in Munich.
|
|
|
169 |
Many of the theoretical ideas originate from the nominal logic project - a wonderful project headed
|
|
|
170 |
by <A HREF="http://www.cl.cam.ac.uk/~amp12/">Prof. Andrew Pitts</A>.
|
|
|
171 |
The aim of my work is to make formal reasoning involving binders as simple as
|
|
|
172 |
on paper and the hope is to lure
|
|
|
173 |
<A HREF="http://alliance.seas.upenn.edu/~plclub/cgi-bin/poplmark/index.php?title=The_POPLmark_Challenge#Vision">masses</A> to automated
|
|
|
174 |
theorem proving. My funding for this work was provided in 2004 and 2005 by a research
|
|
|
175 |
fellowship from the
|
|
|
176 |
<A HREF="http://en.wikipedia.org/wiki/Alexander_von_Humboldt">Alexander-von-Humboldt</A>
|
|
|
177 |
<A HREF="http://www.humboldt-foundation.de/web/home.html">foundation</A>. During this time I was a visitor in the group of
|
|
|
178 |
<A HREF="http://www.mathematik.uni-muenchen.de/~schwicht/">Prof. Helmut Schwichtenberg</A>.
|
|
|
179 |
Since 2006 this work is supported by an
|
|
|
180 |
<A HREF="http://en.wikipedia.org/wiki/Emmy_Noether">Emmy-Noether</A>
|
|
|
181 |
<A HREF="http://www.dfg.de/en/research_funding/programmes/individual/emmy_noether/in_brief/index.html">fellowship</A>.
|
|
|
182 |
There is a <A HREF="http://isabelle.in.tum.de/nominal/">webpage</A> and a
|
|
|
183 |
<A HREF="https://mailmanbroy.informatik.tu-muenchen.de/mailman/listinfo/nominal-isabelle">mailing list</A>
|
|
|
184 |
about Nominal Isabelle. It also includes a list of projects that use Nominal Isabelle.
|
|
|
185 |
Users of Nominal Isabelle had their papers appearing at LICS, POPL, FOSSACS, SOS, TPHOLs and CPP.
|
|
|
186 |
</TD>
|
|
|
187 |
</TR>
|
|
|
188 |
|
|
|
189 |
<TR>
|
|
|
190 |
<TD BGCOLOR="#FFFFFF" WIDTH="75%">
|
|
|
191 |
<B>Myhill-Nerode and Regular Expressions</B>
|
|
63
|
192 |
Out of frustration of having to teach reasoning in theorem provers with worn-out examples like
|
|
2
|
193 |
fib and even/odd, we implemented a large part of regular language theory in Isabelle/HOL.
|
|
|
194 |
This <A HREF="http://afp.sourceforge.net/devel-entries/Myhill-Nerode.shtml">implementation</A>
|
|
|
195 |
gives rise to much more interesting examples, as shown
|
|
|
196 |
<A HREF="http://www.cs.cmu.edu/~rwh/papers/regexp/jfp.ps">here</A> and
|
|
|
197 |
<A HREF="http://ropas.snu.ac.kr/~kwang/paper/06-jfp-yi.pdf">here</A>. It turns out that
|
|
|
198 |
formalisations of automata theory are a huge
|
|
|
199 |
<A HREF="https://lists.cam.ac.uk/pipermail/cl-isabelle-users/2005-September/msg00012.html">pain</A>
|
|
37
|
200 |
in theorem provers, especially in those that are based on HOL.
|
|
2
|
201 |
We therefore went against the
|
|
|
202 |
<A HREF="http://books.google.com/books?id=8lKyxS8_CNoC&pg=PA14&source=gbs_toc_r&cad=4#v=onepage&q&f=false">mainstream</A>
|
|
|
203 |
and used in our formalisation regular expressions exclusively,
|
|
|
204 |
because they are much more convenient for formal reasoning. The results we
|
|
|
205 |
formalised include: the Myhill-Nerode theorem, the closure of regular languages
|
|
|
206 |
under complementation, finiteness of derivatives of regular expressions and a surprising
|
|
|
207 |
result about Subseq, which according to
|
|
|
208 |
this
|
|
|
209 |
<A HREF="http://blog.computationalcomplexity.org/2006/01/theorem-that-should-be-better-known.html">blog</A>
|
|
|
210 |
should be better known. This is joint work with Prof. Xingyuan
|
|
|
211 |
Zhang and his student Chunhan Wu from the
|
|
|
212 |
<A HREF="http://www.ust.com.cn/">PLA University of Science and Technology</A> in Nanjing.
|
|
|
213 |
My funding for this work came from the
|
|
|
214 |
<A HREF="http://www.sinogermanscience.org.cn/">Chinese-German Research Centre</A>.
|
|
|
215 |
</TD>
|
|
|
216 |
</TR>
|
|
|
217 |
|
|
|
218 |
<TR>
|
|
|
219 |
<TD BGCOLOR="#FFFFFF" WIDTH="75%">
|
|
|
220 |
<B>Nominal Unification and Alpha-Prolog</B>
|
|
24
|
221 |
<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Unification">Nominal unification</A> is one outcome of
|
|
2
|
222 |
my involvement in the nominal logic project in Cambridge. Another is the logic programming language
|
|
|
223 |
alpha-Prolog (joint work with <A HREF="http://homepages.inf.ed.ac.uk/jcheney/">Dr James Cheney</A>),
|
|
|
224 |
which uses nominal unification - click for details
|
|
|
225 |
<A HREF="http://homepages.inf.ed.ac.uk/jcheney/programs/aprolog/">here</A>.
|
|
|
226 |
The nominal unification algorithm has been
|
|
24
|
227 |
<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Unification">formally verified</A> in Isabelle. This
|
|
2
|
228 |
was possible since this unification algorithm is formulated in a simple first-order language
|
|
|
229 |
(unlike other algorithms for higher-order unification).
|
|
|
230 |
<A HREF="http://www.cs.indiana.edu/~dfried/">Prof. Daniel Friedman</A> and his group use nominal
|
|
|
231 |
unification in their alpha-Kanren system implemented in Scheme.
|
|
24
|
232 |
<A HREF="http://www.inf.kcl.ac.uk/staff/maribel/">Prof. Maribel Fernandez</A> and her student
|
|
2
|
233 |
improved the nominal unification algorithm to be quadratic.
|
|
|
234 |
My funding for this work was provided through a research fellowship from
|
|
|
235 |
<A HREF="http://www.corpus.cam.ac.uk">Corpus Christi College</A>, Cambridge.
|
|
|
236 |
</TD>
|
|
|
237 |
</TR>
|
|
|
238 |
|
|
|
239 |
<TR>
|
|
|
240 |
<TD BGCOLOR="#FFFFFF" WIDTH="75%">
|
|
|
241 |
<B>Classical Logic</B>
|
|
|
242 |
I was Ph.D. student in the University of Cambridge
|
|
|
243 |
<A HREF="http://www.cl.cam.ac.uk">Computer Laboratory</A>
|
|
|
244 |
and for three years
|
|
|
245 |
called Gonville and Caius College my home. I was very lucky to have
|
|
|
246 |
<A HREF="http://research.microsoft.com/~gmb/">Dr Gavin Bierman</A>
|
|
|
247 |
as supervisor. My research in Cambridge was also very much influenced by
|
|
|
248 |
<A HREF="http://www.dpmms.cam.ac.uk/~martin/">Prof. Martin Hyland</A>.
|
|
|
249 |
Some details on my thesis "Classical Logic and Computation" are
|
|
24
|
250 |
<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/PhD/index.html">elsewhere</A>, including
|
|
|
251 |
a <A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Cut/cutapplet.html">Java Applet</A> that
|
|
2
|
252 |
'visualises' some of the results from the thesis. I completed the writing of
|
|
|
253 |
the thesis in <A HREF="http://iml.univ-mrs.fr/ldp/">Marseille</A> in the group of
|
|
|
254 |
<A HREF="http://iml.univ-mrs.fr/~girard/">Prof. Jean-Yves Girard</A>. My study in
|
|
|
255 |
Cambridge was funded by two <A HREF="http://www.daad.de/index.html">scholarships</a>
|
|
|
256 |
from the German government; my year in Marseille by a TMR-fellowship from the EU.
|
|
|
257 |
My PhD was also one starting point for the EPSRC Project on the Semantics of Classical
|
|
64
|
258 |
Proofs. The strong normalisation result in the PhD has been used in 2007 by
|
|
2
|
259 |
<A HREF="http://www.loria.fr/~ckirchne/hot.html">Prof. Claude Kirchner</A> and his
|
|
66
|
260 |
students for proving consistency of their superdeduction system lemuridae.
|
|
2
|
261 |
</TD>
|
|
|
262 |
</TR>
|
|
|
263 |
|
|
|
264 |
|
|
|
265 |
|
|
|
266 |
<TR>
|
|
|
267 |
<TD BGCOLOR="#FFFFFF" WIDTH="75%">
|
|
|
268 |
<B>Forum</B>
|
|
|
269 |
I implemented Forum, a programming language based on classical linear logic,
|
|
|
270 |
as my M.Phil. thesis. This was joint work with
|
|
24
|
271 |
<A HREF="http://www.inf.st-and.ac.uk/~rd/">Dr Roy Dyckhoff</A>.
|
|
2
|
272 |
Details can be found
|
|
24
|
273 |
<A HREF="http://www.inf.st-and.ac.uk/~rd/logic/nonmac/">here</A> and
|
|
2
|
274 |
<A HREF="http://www.lix.polytechnique.fr/Labo/Dale.Miller/forum/">here</A>. During my
|
|
|
275 |
M.Phil study I spent one month in Philadelphia invited by
|
|
|
276 |
<A HREF="http://www.lix.polytechnique.fr/~dale/">Prof. Dale Miller</A>.
|
|
|
277 |
</TD>
|
|
|
278 |
</TR>
|
|
|
279 |
|
|
|
280 |
<TR>
|
|
|
281 |
<TD BGCOLOR="#FFFFFF" WIDTH="75%">
|
|
|
282 |
<B>G4ip</B> An implementation of G4ip using the imperative language Pizza can be found
|
|
24
|
283 |
<A HREF="http://www.inf.kcl.ac.uk/staff/urbanc/Prover/index.html">here</A>.
|
|
2
|
284 |
<A HREF="http://pizzacompiler.sourceforge.net">Pizza</A> is a conservative
|
|
|
285 |
extension of Java and a precursor of Scala. The implementation illustrates the technique of success
|
|
|
286 |
continuations.
|
|
|
287 |
</TD>
|
|
|
288 |
</TR>
|
|
|
289 |
|
|
|
290 |
|
|
|
291 |
</TABLE>
|
|
|
292 |
<P><!-- Created: Tue Mar 4 00:23:25 GMT 1997 -->
|
|
|
293 |
<!-- hhmts start -->
|
|
66
|
294 |
Last modified: Fri Jan 6 18:41:42 GMT 2012
|
|
2
|
295 |
<!-- hhmts end -->
|
|
|
296 |
<a href="http://validator.w3.org/check/referer">[Validate this page.]</a>
|
|
|
297 |
|
|
|
298 |
</BODY>
|
|
|
299 |
</HTML>
|