diff -r 9e036cad8654 -r f329c1f3b365 index.html --- a/index.html Sat Oct 22 10:37:59 2011 +0100 +++ b/index.html Sat Oct 22 10:43:10 2011 +0100 @@ -1,10 +1,280 @@ - - - - Minimal HTML Document - - - -Test - - + + + +Homepage of Christian Urban + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
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+ + + +		 + + + + + + +
+

Christian Urban

+ +E-mail +urbanc at in tum de
+
+ +Address +Institute for Computer Science +at the TU Munich (IV), Boltzmannstrasse 3, D-85748 Garching, Germany. +

+ +Fax +49 89 289 17307 +		 + +
+

+Isabelle Documentation Project (contains now a draft of a 200-page tutorial on Isabelle programming)
+

+Current Position +I have been awarded an +Emmy-Noether +fellowship +to head an independent research group in +the Computer Science Department at the +TU Munich. This group co-operates +with the Theorem Proving Group +chaired by Prof. Tobias Nipkow and +is accommodated by the institute of +Prof. Manfred Broy. +

+ +Past Positions +Between September 2008 and February 2009, I was an invited research fellow in +the Department of Computer Science 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. +

+ +Research Interests theorem provers, programming languages, compilers, +algorithms, proof theory, type systems, concurrency, lambda calculus, unification, +regular expressions, computability, complexity, functional and logic programming. +

+ +Conferences +UNIF'06 (member of PC), +LFMTP'07 (member of PC), +LFMTP'08 (PC co-chair), +WMM'08 (member of PC), +LSFA'08 (invited speaker), +TAASN'09 (member of PC), +LSFA'09 (member of PC), +IDW'09 (organiser), +WMM'09 (PC chair), +TPHOLs'09 (PC co-chair), +Automatheo'10 (member of PC), +ITP'10 (member of PC), +UNIF'10 (invited speaker), +WMM'10 (invited speaker), +IDW'10 (co-organiser), +CPP'11 (member of PC), +RTA'11 (member of PC), +LFMTP'11 (member of PC) +
+ +

+Nominal Isabelle +I currently work on Nominal +Isabelle. This is joint work with +Dr Stefan Berghofer, +Dr Markus Wenzel, +Dr Cezary Kaliszyk and +the Isabelle-team in Munich. +Many of the theoretical ideas originate from the nominal logic project - a wonderful project headed +by Prof. Andrew Pitts. +The aim of my work is to make formal reasoning involving binders as simple as +on paper and the hope is to lure +masses to automated +theorem proving. My funding for this work was provided in 2004 and 2005 by a research +fellowship from the +Alexander-von-Humboldt +foundation. During this time I was a visitor in the group of +Prof. Helmut Schwichtenberg. +Since 2006 this work is supported by an +Emmy-Noether +fellowship. +There is a webpage and a +mailing list +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 and CPP. +
+Myhill-Nerode and Regular Expressions +Out of frustration of having to teach inductions in theorem provers using worn-out examples like +fib and even/odd, we implemented a large part of regular language theory in Isabelle/HOL. +This implementation +gives rise to much more interesting examples, as shown +here and +here. It turns out that +formalisations of automata theory are a huge +pain +in theorem provers, especially in those that are HOL-based. +We therefore went against the +mainstream +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 +blog +should be better known. This is joint work with Prof. Xingyuan +Zhang and his student Chunhan Wu from the +PLA University of Science and Technology in Nanjing. +My funding for this work came from the +Chinese-German Research Centre. +
+Nominal Unification and Alpha-Prolog +Nominal unification is one outcome of +my involvement in the nominal logic project in Cambridge. Another is the logic programming language +alpha-Prolog (joint work with Dr James Cheney), +which uses nominal unification - click for details +here. +The nominal unification algorithm has been +formally verified in Isabelle. This +was possible since this unification algorithm is formulated in a simple first-order language +(unlike other algorithms for higher-order unification). +Prof. Daniel Friedman and his group use nominal +unification in their alpha-Kanren system implemented in Scheme. +Prof. Maribel Fernandez and her student +improved the nominal unification algorithm to be quadratic. +My funding for this work was provided through a research fellowship from +Corpus Christi College, Cambridge. +
+Classical Logic +I was Ph.D. student in the University of Cambridge +Computer Laboratory +and for three years +called Gonville and Caius College my home. I was very lucky to have +Dr Gavin Bierman +as supervisor. My research in Cambridge was also very much influenced by +Prof. Martin Hyland. +Some details on my thesis "Classical Logic and Computation" are +elsewhere, including +a Java Applet that +'visualises' some of the results from the thesis. I completed the writing of +the thesis in Marseille in the group of +Prof. Jean-Yves Girard. My study in +Cambridge was funded by two scholarships +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 recently been used by +Prof. Claude Kirchner and his +students to prove consistency for their superdeduction system lemuridae. +
+Forum +I implemented Forum, a programming language based on classical linear logic, +as my M.Phil. thesis. This was joint work with +Dr Roy Dyckhoff. +Details can be found +here and +here. During my +M.Phil study I spent one month in Philadelphia invited by +Prof. Dale Miller. +
+G4ip An implementation of G4ip using the imperative language Pizza can be found +here. +Pizza is a conservative +extension of Java and a precursor of Scala. The implementation illustrates the technique of success +continuations. +
+

+ +Last modified: Mon Sep 5 10:11:36 BST 2011 + +[Validate this page.] + + + +