diff -r 05e5d68c9627 -r f1be8028a4a9 index.html~ --- /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 @@ + + + +Homepage of Christian Urban + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
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Christian Urban

+ +E-mail +christian.urban at kcl ac uk
+
+ +Address +Department of Informatics, +King's College London, +Strand, London WC2R 2LS, UK. My office is S1.27 on the 1st floor of the Strand Building. +
+ +		 + +
+

+Isabelle Programming Tutorial (draft of a 200-page tutorial on Isabelle programming)

+

+Current Position +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 +here, an associate professorship +here, +and full professorships +here and +here. +I thank all people involved for their efforts. +

+ +Past Positions +In April 2006, I was awarded an Emmy-Noether +fellowship, which I held at the TU Munich until +September 2011. +Between September 2008 and February 2009, I was an invited research scientist 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 funded by two scholarships from the German Academic Exchange +Service (DAAD). +

+ +Skolem Award 2015 Together with +Christine Tasson, I was awarded a +Thoralf Skolem Award, a ten-year + test-of-time award from CADE, for our + paper + on Nominal Techniques in Isabelle/HOL from 2005. +

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

+ +Teaching 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 NMS Faculty.

+ + +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), +ITP'14 (member of PC), +MKM'15 (member of PC), +ITP'15 (PC co-chair) +

+ +ITP'15 took place in Nanjing organised +by Xingyuan Zhang and me
+

+ +Current PhD Fahad Ausaf
+Former RAs Chunhan Wu, Cezary Kaliszyk, +Julien Narboux +

+Nominal Isabelle +I currently work on Nominal +Isabelle 2. This is joint work with +Dr Stefan Berghofer, +Dr Markus Wenzel, +Dr Cezary Kaliszyk, +Dr Tjark Weber 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, CPP, SEFM, +the Haskell Symposium and +in the Journal of Automated Reasoning. +
+Myhill-Nerode and Regular Expressions +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 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 based on HOL. +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. We also answered a +question 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 +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 been used in 2007 by +Prof. Claude Kirchner and his +students for proving consistency of 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, 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. +
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+ Last modified: Fri Nov 13 13:13:26 GMT 2015 +[Validate this page.] + +