Jun.-Prof. Dr. rer. nat. habil. Janis Voigtländer

(Juniorprofessor - Programmiersprachen / Programming Languages / Програмни Езици)

	Address:	University of Bonn Institute for Computer Science Department III Römerstraße 164 D - 53117 Bonn Germany
	Room:	A 224
	Phone:	+49 228 73 4535
	Fax:	+49 228 73 4382 (please include a cover page)
	E-mail:

News:

• Funding for my DFG project on free theorems was extended for another year (covering a post-doc research assistant position at 75%, as applied for).
• Funding for a completely new DFG project on bidirectional transformations has also been granted (covering a PhD research assistant position at 100% for three years).
• I am chairing the Haskell Symposium 2012.

Current Teaching (in German):

Außerdem organisiere ich das Informatik-Kolloquium.

Teaching Overview

Research Focus:

One area of particular interest to me recently is bidirectional transformations. I just got (separate) DFG-funding for work on this topic.

Go to Talk Slides

Grants:

• I lead two DFG-funded projects (see above; funding summing up to 81 person months at research position level).
• A joint DAAD-PROCOPE project (sponsoring mutual visits) with Lutz Strassburger and other partners at INRIA Saclay in France will run throughout 2012 and 2013.
• I held a SICSA Distinguished Visiting Fellowship (sponsoring visits to the group Mathematically Structured Programming at University of Strathclyde, Glasgow, and the Laboratory for Foundations of Computer Science at University of Edinburgh) from 2009 to 2011. The hosts were Patricia Johann and Alex Simpson.
• I ran a joint DAAD-FCT project (sponsoring mutual visits) with Portuguese partners Joao Saraiva and Joao Paulo Fernandes, both at the University of Minho, throughout 2010.
• I spent a month with the group of Zhenjiang Hu under a Short-Term JSPS Postdoctoral Fellowship in February/March 2010.

Activities:

I am chair of the steering committee for the PEPM workshop series.

I am a member of the steering committee for the Haskell Symposium series.

I co-edited a special issue of Higher-Order and Symbolic Computation devoted to selected papers from PEPM'10.

I serve(d) as chair or co-chair of the program committees for Haskell'12, BX'12, ATPS'12, and PEPM'10. I serve(d) on the program committees for RC'12, ICMT'12, HaL7, WFLP'11, ICMT'11, HaL6, IFL'10, HaL5, APLAS'09, ATPS'09, Haskell'09, HaL4, WST'09, PEPM'09, and ICFP'07.

I serve on the external review committee for POPL'13.

I co-organized CSXW'11.

Since 2008, I serve as editor of the Haskell Communities and Activities Report (appearing twice a year).

I was the keynote speaker at LDTA'12.

I was one of two keynote speakers at PPL'10 (Japanese conference on Programming and Programming Languages, about 130 participants).

This summer, I serve on the reading committee for Jose Pedro Magalhaes's PhD (at University of Utrecht, Netherlands).

Also in the past, I served on the PhD committees of some very fine candidates (and now PhD holders...):

• Holger Bock Axelsen, at University of Copenhagen, Denmark, in December 2011
• Jean-Philippe Bernardy, at Chalmers University of Gothenburg, Sweden, in June 2011
• Joao Paulo Fernandes, at University of Minho, Portugal, in March 2009

Ich organisierte die Bonner Hochschultage der Informatik 2012, 2011 und 2010.

Publications: (@dblp, @citeulike, @acm, @researchr)

Edited (sorted by recency):

• F. Hermann and J. Voigtländer
  Special issue of Electronic Communications of the EASST containing revised and extended versions of selected articles from BX'12, the First International Workshop on Bidirectional Transformations, to appear.
• F. Huch and J. Voigtländer
  Proceedings of the 5. Arbeitstagung Programmiersprachen der GI-Fachgruppe "Programmiersprachen und Rechenkonzepte" im Rahmen der Software Engineering 2012, ATPS'12, Berlin, Germany, GI, February 2012.
• J. Gallagher and J. Voigtländer
  Special issue of Higher-Order and Symbolic Computation containing extended versions of selected articles from PEPM'10, the ACM SIGPLAN 2010 Workshop on Partial Evaluation and Program Manipulation. Springer-Verlag, November 2011.
  The editorial is available from http://dx.doi.org/10.1007/s10990-011-9081-0.
• J. Gallagher and J. Voigtländer
  Proceedings of the 2010 ACM SIGPLAN Workshop on Partial Evaluation and Program Manipulation, PEPM'10, Madrid, Spain, © ACM Press, January 2010.

Book chapter:

• N. Foster, K. Matsuda, and J. Voigtländer
  Three Complementary Approaches to Bidirectional Programming
  In Spring School on Generic and Indexed Programming (SSGIP'10), Oxford, England, revised lecture notes, LNCS, to appear.

Journals (sorted by recency):

• D. Seidel and J. Voigtländer
  Refined Typing to Localize the Impact of Forced Strictness on Free Theorems (bib+abstract)
  Acta Informatica, volume 48(3), pages 191-211, Springer-Verlag, 2011.
  The definitive version of this work is available from http://dx.doi.org/10.1007/s00236-011-0136-9.
  The implementation of the algorithm developed in this paper is accessible via a web interface here.
• P. Johann and J. Voigtländer
  A family of syntactic logical relations for the semantics of Haskell-like languages (bib+abstract)
  Information and Computation, volume 207(2), pages 341-368, Elsevier, 2009.
  The definitive version of this work is available from http://dx.doi.org/10.1016/j.ic.2007.11.009.
• J. Voigtländer and P. Johann
  Selective strictness and parametricity in structural operational semantics, inequationally (bib+abstract)
  Theoretical Computer Science, volume 388(1-3), pages 290-318, Elsevier, 2007.
  The definitive version of this work is available from http://dx.doi.org/10.1016/j.tcs.2007.09.014.
• J. Voigtländer
  Formal Efficiency Analysis for Tree Transducer Composition (bib+abstract)
  Theory of Computing Systems, volume 41(4), pages 619-689, Springer-Verlag, 2007.
  The original publication is available from http://dx.doi.org/10.1007/s00224-006-1235-9.
• J. Giesl, A. Kühnemann, and J. Voigtländer
  Deaccumulation techniques for improving provability (bib+abstract)
  Journal of Logic and Algebraic Programming, volume 71(2), pages 79-113, Elsevier, 2007.
  The definitive version of this work is available from http://dx.doi.org/10.1016/j.jlap.2006.11.001.
• P. Johann and J. Voigtländer
  The Impact of seq on Free Theorems-Based Program Transformations (bib+abstract)
  Fundamenta Informaticae, volume 69(1-2), pages 63-102, IOS Press, 2006.
• J. Voigtländer
  Using Circular Programs to Deforest in Accumulating Parameters (bib+abstract)
  Higher-Order and Symbolic Computation, volume 17(1-2), pages 129-163, © Kluwer Academic Publishers, 2004.
  The definitive version of this work is available from http://dx.doi.org/10.1023/B:LISP.0000029450.36668.cb.
• J. Voigtländer and A. Kühnemann
  Composition of functions with accumulating parameters (bib+abstract, proof appendix)
  Journal of Functional Programming, volume 14(3), pages 317-363, © Cambridge University Press, 2004.

Proceedings (sorted by acceptance rate):

P. Johann and J. Voigtländer Free Theorems in the Presence of seq (bib+abstract) In 31st Symposium on Principles of Programming Languages (POPL'04, acceptance rate 29/176), Venice, Italy, Proceedings, volume 39(1) of SIGPLAN Notices, pages 99-110, © ACM Press, January 2004. This (authors') version of the work is posted here by permission of ACM for your personal use; not for redistribution. The definitive version was published as indicated (cf. also http://doi.acm.org/10.1145/982962.964010). It is available via the ACM DL Author-ize feature here. An extended version of this work appeared in Fundamenta Informaticae, see above.

J. Voigtländer Much Ado about Two: A Pearl on Parallel Prefix Computation (bib+abstract) In 35th Symposium on Principles of Programming Languages (POPL'08, acceptance rate 35/212), San Francisco, California, Proceedings, volume 43(1) of SIGPLAN Notices, pages 29-35, © ACM Press, January 2008. This (author's) version of the work is posted here by permission of ACM for your personal use; not for redistribution. The definitive version was published as indicated (cf. also http://doi.acm.org/10.1145/1328897.1328445). It is available via the ACM DL Author-ize feature here.

J. Voigtländer Bidirectionalization for Free! (bib+abstract) In 36th Symposium on Principles of Programming Languages (POPL'09, acceptance rate 36/160), Savannah, Georgia, Proceedings, volume 44(1) of SIGPLAN Notices, pages 165-176, © ACM Press, January 2009. This (author's) version of the work is posted here by permission of ACM for your personal use; not for redistribution. The definitive version was published as indicated (cf. also http://doi.acm.org/10.1145/1480881.1480904). It is available via the ACM DL Author-ize feature here. A web interface to the library developed in this paper is accessible here.

P. Johann, A. Simpson, and J. Voigtländer A Generic Operational Metatheory for Algebraic Effects (bib+abstract) In 25th Symposium on Logic in Computer Science (LICS'10, acceptance rate 40/149), Edinburgh, Scotland, Proceedings, pages 209-218, © IEEE Press, July 2010.

J. Voigtländer Proving Correctness via Free Theorems: The Case of the destroy/build-Rule (bib+abstract) In Symposium on Partial Evaluation and Semantics-Based Program Manipulation (PEPM'08, acceptance rate 20/74), San Francisco, California, Proceedings, pages 13-20, © ACM Press, January 2008. This (author's) version of the work is posted here by permission of ACM for your personal use; not for redistribution. The definitive version was published as indicated (cf. also http://doi.acm.org/10.1145/1328408.1328412). It is available via the ACM DL Author-ize feature here. The tool used in this paper to derive free theorems is now accessible via a web interface here.

J. Giesl, A. Kühnemann, and J. Voigtländer Deaccumulation - Improving Provability (bib+abstract) In 8th Asian Computing Science Conference (ASIAN'03, acceptance rate 16/53), Mumbai, India, Proceedings, volume 2896 of LNCS, pages 146-160, © Springer-Verlag, December 2003. An extended version of this work appeared in Journal of Logic and Algebraic Programming, see above.

J. Voigtländer Concatenate, Reverse and Map Vanish For Free (bib+abstract) In 7th International Conference on Functional Programming (ICFP'02, acceptance rate 24/76), Pittsburgh, Pennsylvania, Proceedings, volume 37(9) of SIGPLAN Notices, pages 14-25, © ACM Press, October 2002. This (author's) version of the work is posted here by permission of ACM for your personal use; not for redistribution. The definitive version was published as indicated (cf. also http://doi.acm.org/10.1145/583852.581481). It is available via the ACM DL Author-ize feature here.

J. Voigtländer Free Theorems Involving Type Constructor Classes (bib+abstract) In 14th International Conference on Functional Programming (ICFP'09, acceptance rate 32/101), Edinburgh, Scotland, Proceedings, volume 44(9) of SIGPLAN Notices, pages 173-184, © ACM Press, September 2009. This (author's) version of the work is posted here by permission of ACM for your personal use; not for redistribution. The definitive version was published as indicated (cf. also http://doi.acm.org/10.1145/1596550.1596577). It is available via the ACM DL Author-ize feature here. A video of the conference presentation is available here.

J. Voigtländer, Z. Hu, K. Matsuda, and M. Wang Combining Syntactic and Semantic Bidirectionalization (bib+abstract) In 15th International Conference on Functional Programming (ICFP'10, acceptance rate 33/99), Baltimore, Maryland, Proceedings, volume 45(9) of SIGPLAN Notices, pages 181-192, © ACM Press, September 2010. This (author's) version of the work is posted here by permission of ACM for your personal use; not for redistribution. The definitive version was published as indicated (cf. also http://doi.acm.org/10.1145/1863543.1863571). It is available via the ACM DL Author-ize feature here. A web interface to the methods discussed in this paper is accessible here.

J. Voigtländer Semantics and Pragmatics of New Shortcut Fusion Rules (bib+abstract) In 9th International Symposium on Functional and Logic Programming (FLOPS'08, acceptance rate 20/59), Ise, Japan, Proceedings, volume 4989 of LNCS, pages 163-179, © Springer-Verlag, April 2008.

D. Seidel and J. Voigtländer Automatically Generating Counterexamples to Naive Free Theorems (bib+abstract) In 10th International Symposium on Functional and Logic Programming (FLOPS'10, acceptance rate 21/49), Sendai, Japan, Proceedings, volume 6009 of LNCS, pages 175-190, © Springer-Verlag, April 2010. The implementation of the algorithm presented in this paper is accessible via a web interface here.

J.P. Fernandes, J. Saraiva, D. Seidel, and J. Voigtländer Strictification of Circular Programs (bib+abstract) In Workshop on Partial Evaluation and Program Manipulation (PEPM'11, acceptance rate 15/35), Austin, Texas, Proceedings, pages 131-140, © ACM Press, January 2011. This (author's) version of the work is posted here by permission of ACM for your personal use; not for redistribution. The definitive version was published as indicated (cf. also http://doi.acm.org/10.1145/1929501.1929526). It is available via the ACM DL Author-ize feature here.

J. Voigtländer Asymptotic Improvement of Computations over Free Monads (bib+abstract) In 9th International Conference on Mathematics of Program Construction (MPC'08, acceptance rate 18/41), Marseille, France, Proceedings, volume 5133 of LNCS, pages 388-403, © Springer-Verlag, July 2008.

D. Seidel and J. Voigtländer Proving Properties About Functions on Lists Involving Element Tests In 20th International Workshop on Algebraic Development Techniques (WADT'10), Schloss Etelsen, Germany, Revised Selected Papers (acceptance rate 15/32), volume 7137 of LNCS, pages 270-286, © Springer-Verlag, February 2012.

J. Voigtländer Conditions for Efficiency Improvement by Tree Transducer Composition (bib+abstract) In 13th International Conference on Rewriting Techniques and Applications (RTA'02, acceptance rate 20/40), Copenhagen, Denmark, Proceedings, volume 2378 of LNCS, pages 222-236, © Springer-Verlag, July 2002.

F. Stenger and J. Voigtländer Parametricity for Haskell with Imprecise Error Semantics (bib+abstract) In 9th International Conference on Typed Lambda Calculi and Applications (TLCA'09, acceptance rate 27/53), Brasília, Brazil, Proceedings, volume 5608 of LNCS, pages 294-308, © Springer-Verlag, July 2009.

J. Voigtländer Ideas for Connecting Inductive Program Synthesis and Bidirectionalization In Workshop on Partial Evaluation and Program Manipulation (PEPM'12, acceptance rate 19/37), Philadelphia, Pennsylvania, Proceedings, pages 39-42, © ACM Press, January 2012. This (author's) version of the work is posted here by permission of ACM for your personal use; not for redistribution. The definitive version was published as indicated (cf. also http://dx.doi.org/10.1145/2103746.2103757). It is available via the ACM DL Author-ize feature here.

J. Voigtländer Using Circular Programs to Deforest in Accumulating Parameters (bib+abstract) In Asian Symposium on Partial Evaluation and Semantics-Based Program Manipulation (ASIA-PEPM'02, acceptance rate 11/21), Aizu, Japan, Proceedings, pages 126-137, © ACM Press, September 2002. This (author's) version of the work is posted here by permission of ACM for your personal use; not for redistribution. The definitive version was published as indicated (cf. also http://doi.acm.org/10.1145/568173.568187). It is available via the ACM DL Author-ize feature here. An extended version of this work appeared in Higher-Order and Symbolic Computation, see above.

J. Christiansen, D. Seidel, and J. Voigtländer An Adequate, Denotational, Functional-Style Semantics for Typed FlatCurry (bib+abstract) In 19th International Workshop on Functional and (Constraint) Logic Programming (WFLP'10, acceptance rate 12/15), Madrid, Spain, Revised Selected Papers (acceptance rate 8/12), volume 6559 of LNCS, pages 119-136, © Springer-Verlag, 2011. We found that two of the conjectures in the paper do not hold, see the online appendix for details. There is also a revised version available as a technical report, incorporating the corrections, see below.

J. Christiansen, D. Seidel, and J. Voigtländer Free Theorems for Functional Logic Programs (bib+abstract) In 4th Workshop on Programming Languages meets Program Verification (PLPV'10, acceptance rate 7/10), Madrid, Spain, Proceedings, pages 39-48, © ACM Press, January 2010. This (authors') version of the work is posted here by permission of ACM for your personal use; not for redistribution. The definitive version was published as indicated (cf. also http://doi.acm.org/10.1145/1707790.1707797). It is available via the ACM DL Author-ize feature here. An abstract-only version appeared in volume 44(11) of SIGPLAN Notices, page 7 (http://doi.acm.org/10.1145/1816027.1816035).

D. Seidel and J. Voigtländer Taming Selective Strictness (bib+abstract) In 4. Arbeitstagung Programmiersprachen (ATPS'09, acceptance rate 8/11) der GI-Fachgruppe "Programmiersprachen und Rechenkonzepte" im Rahmen der GI-Jahrestagung Informatik 2009, Lübeck, Germany, Proceedings, volume 154 of Lecture Notes in Informatics, pages 2916-2930, GI, October 2009. An extended version of this work appeared in Acta Informatica, see above.

D. Seidel and J. Voigtländer Improvements for Free In 9th Workshop on Quantitative Aspects of Programming Languages (QAPL'11, acceptance rate 11/13), Saarbrücken, Germany, Post-Proceedings, volume 57 of EPTCS, pages 89-103, 2011.

Theses:

• J. Voigtländer
  Types for Programming and Reasoning
  Habilitation thesis, Technische Universität Dresden, defended in July 2009.
• J. Voigtländer
  Tree Transducer Composition as Program Transformation (bib+abstract)
  PhD thesis, Technische Universität Dresden, defended in January 2005.
  This thesis is also available as a book.
• J. Voigtländer
  Composition of restricted Macro Tree Transducers (bib+abstract)
  Master thesis, Technische Universität Dresden, defended in April 2001.
  An article based on this thesis appeared in Journal of Functional Programming, see above.

Technical Reports:

• J. Christiansen, D. Seidel, and J. Voigtländer
  An Adequate, Denotational, Functional-Style Semantics for Typed FlatCurry without Letrec (bib+abstract)
  Technical Report IAI-TR-2011-1, University of Bonn, March 2011.
• D. Seidel and J. Voigtländer
  Taming Selective Strictness (bib+abstract)
  Technical Report TUD-FI09-06, Technische Universität Dresden, June 2009.
• F. Stenger and J. Voigtländer
  Parametricity for Haskell with Imprecise Error Semantics (bib+abstract)
  Technical Report TUD-FI08-08, Technische Universität Dresden, November 2008.
• J. Voigtländer and P. Johann
  Selective Strictness and Parametricity in Structural Operational Semantics (bib+abstract)
  Technical Report TUD-FI06-02, Technische Universität Dresden, June 2006.
  A revised version of this work appeared in Theoretical Computer Science, see above.
• J. Giesl, A. Kühnemann, and J. Voigtländer
  Deaccumulation Techniques for Improving Provability (bib+abstract)
  Technical Report TUD-FI05-14, Technische Universität Dresden, December 2005.
  A slightly revised version of this work appeared in Journal of Logic and Algebraic Programming, see above.
• J. Voigtländer
  Formal Efficiency Analysis for Tree Transducer Composition (bib+abstract)
  Technical Report TUD-FI04-08, Technische Universität Dresden, June 2004.
  An abridged and revised version of this work appeared in Theory of Computing Systems, see above.
• J. Voigtländer and A. Kühnemann
  Composition of Functions with Accumulating Parameters (bib+abstract)
  Technical Report TUD-FI01-08, Technische Universität Dresden, August 2001.
  A much revised version of this work appeared in Journal of Functional Programming, see above.
• A. Kühnemann and J. Voigtländer
  Tree Transducer Composition as Deforestation Method for Functional Programs (bib+abstract)
  Technical Report TUD-FI01-07, Technische Universität Dresden, August 2001.

Slides of some Talks:

• Programming Language Approaches to Bidirectional Transformation
  as invited speaker at LDTA'12, Tallinn, March 31, 2012.
• Ideas for Connecting Inductive Program Synthesis and Bidirectionalization
  at PEPM'12, Philadelphia, January 23, 2012.
• Type-Based Reasoning about Efficiency
  as ToPS seminar at National Institute of Informatics, Tokyo, August 3, 2011.
• View Update: Programmiersprachliche Techniken für Bidirektionale Transformation
  as colloquium at Universität Bamberg, June 16, 2011.
• Parametricity-Based Reasoning about Efficiency
  as FP talk at Chalmers University of Gothenburg, June 8, 2011.
• Improvements for Free
  at IFIP WG 2.1 meeting #67, Reykjavik, May 25, 2011.
• Free Theorems about Monadic Code
  at EWCE'11, Ljubljana, March 18, 2011.
• Complement-Based Bidirectionalization (part of tutorial)
  Efficiency of Bidirectional Transformations (position statement)
  at Dagstuhl Seminar "bx", Dagstuhl, January 17 and 20, 2011.
• Lectures within course "Source Code Analysis and Manipulation" in PhD program at University of Minho, October 18, 2010:
  Semantic Bidirectionalisation
  Free Theorems - Foundations
  Knuth's 0-1-Principle and Beyond
• Combining Syntactic and Semantic Bidirectionalization
  at ICFP'10, Baltimore, September 28, 2010.
• Strictification of Circular Programs
  at IFIP WG 2.1 meeting #66, Atlantic City, September 22+23, 2010.
• Lightweight Program Inversion
  at Dutch HUG Day, Nieuwegein, April 24, 2010.
• Semantic Bidirectionalization and the Constant-Complement Perspective
  at Bi-Trans in ABC'10, Hakone, March 13, 2010.
• Type-Based Reasoning for Real Languages
  as invited speaker at PPL'10, Kotohira, March 4, 2010.
• Knuth's 0-1-Principle and Beyond
  as GRACE seminar at National Institute of Informatics, Tokyo, February 26, 2010.
• Free Theorems Involving Type Constructor Classes
  at ICFP'09, Edinburgh, September 1, 2009.
  A video of this talk is available here.
• News About a Recent Application of Parametricity
  at ISS-AiPL'09, Edinburgh, August 25, 2009.
• Typbasierte Programmtransformation (in German)
  at my Habilitation defense in Dresden, July 14, 2009.
• Parametricity for Haskell with Imprecise Error Semantics
  at TLCA'09, Brasilia, July 2, 2009.
  (similarly held earlier at NWPT'08, Tallinn, November 19, 2008)
• Short Course "Free Theorems and Applications" at University of Edinburgh, April 22-24, 2009:
  Free Theorems - Foundations
  Knuth's 0-1-Principle and Beyond
  Free Theorems and "Real" Languages
• Semantic Bidirectionalisation
  as LFCS seminar at University of Edinburgh, April 21, 2009.
• Circular vs. Higher-Order Shortcut Fusion
  as departmental talk at University of Minho, March 30, 2009.
• Type-Based Reasoning and Imprecise Errors
  as colloquium at University of Strathclyde in Glasgow, March 6, 2009.
• Type-Based Reasoning and Bidirectional Transformation
  as colloquium at Universität Kiel, February 20, 2009.
• Bidirectionalization for Free!
  at POPL'09, Savannah, January 22, 2009.
• Free Theorems for Bidirectional Transformation (short talk)
  A Constant-Complement Perspective on Bidirectionalization for Free (technical presentation)
  at GRACE-BX'08, Shonan Village, December 15 and 16, 2008.
• Asymptotic Improvement of Computations over Free Monads
  at MPC'08, Marseille, July 16, 2008.
• Freie Theoreme - Was und Wie (in German)
  at HaL3, Leipzig, April 18, 2008.
• Semantics and Pragmatics of New Shortcut Fusion Rules
  at FLOPS'08, Ise, April 15, 2008.
• Much Ado about Two: A Pearl on Parallel Prefix Computation
  at POPL'08, San Francisco, January 10, 2008.
• Proving Correctness via Free Theorems: The Case of the destroy/build-Rule
  at PEPM'08, San Francisco, January 7, 2008.
• Free Theorems - The Basics
  in our working group in Dresden, January 6, 2006.
• Komposition von Baumübersetzern als Programmtransformation (in German)
  at my PhD defense in Dresden, January 24, 2005.
• The Impact of seq on Free Theorems-Based Program Transformations
  in our working group in Dresden, October 22, 2004.
• Elimination of Intermediate Results in Functional Programs
  as colloquium at TU Munich, November 18, 2003.
• Efficiency Improvement by Tree Transducer Composition
  at workshop of the postgraduate programme GK 334, Gohrisch, April 2, 2003.
• Concatenate, Reverse and Map Vanish For Free
  at ICFP'02, Pittsburgh, October 4, 2002.
• Using Circular Programs to Deforest in Accumulating Parameters
  at ASIA-PEPM'02, Aizu, September 14, 2002.
• Conditions for Efficiency Improvement by Tree Transducer Composition
  at RTA'02, Copenhagen, July 23, 2002.
• Composition of Unrestricted Macro Tree Transducers
  in our working group in Dresden, April 19, 2002.

Some organizations I am associated with (mainly as corrector in math competitions):

Also, I am a member of: