CIRCA Report 2007


CIRCA students
Promotions and New Appointments
Research visits


Steve Linton
Colin M Campbell
Ian Gent
Kevin Hammond
Sophie Huczynska
Roy Dyckhoff
Ian Miguel
James Mitchell
John J O’Connor
Martyn Quick
Edmund F Robertson
Colva Roney-Dougal
Nik Ruškuc
Chris Pickard
Andrews Mackenzie
Ulf Leonhardt

Senior Research Fellows

Max Neunhoffer
Tom Kelsey

Research Fellows

Alan Cain
Alexander Konovalov
Peter Nightingale


John McDermott
Angela Miguel

CIRCA Students


Neil Moore (2007-)
Fiona Brunk (2005-)
Yann Peresse (2005-)
Abram Connelly (2005-)
Andy Grayland (2006-)
Jon Bagnall (2007-)
Vladimir Janic (2007-)
Victor Maltcev (2007-)
Andreas Distler (2006-)
Hannah Coutts (2006-)
Andrea Rendl (2006-)
Yohei Negi (2007-)
Morteza Jafarpour (2003-)

Promotions and New Appointments

Max Neunhoffer


Lynn Hynd – to work as a Project Administrator in Physics


Major New Grants in 2007:

  1. EPSRC: Watched Literals and Learning for Constraint Programming EPSRC EP/E030394/1, 2007-2010. £432,356.

  2. Fibre-optical analogue of the event horizon. EPSRC EP/D061830/01 £670,499.

  3. Finiteness Conditions and Index in Semigroups and Monoids. EPSRC PDRF, EP/E043194/1 £203,056. .

  4. Proof Theory and Constraint Satisfaction. EPSRC EP/F031114/1 £44,237.

  5. Backtrack Search in Matrix Groups. Nuffield, £4,600.


Complete List of Current CIRCA Grants

  1. EC: SCIEnce: Symbolic Computation Infrastructure for Europe. Linton, S. Hammond, K. (2006-2011)
  2. EPSRC: Multidisciplinary Critical Mass in Computational Algebra and Applications. Linton, SA, Gent, IP, Miguel, I, Ruskuc, N, Quick, M, Robertson, E, Mackenzie, A, Leonhardt, U. (2005-2010)
  3. EPSRC/Royal Academy of Engineering: An Automated Constraint Modelling Assistant. Miguel, I. Research Fellowship. (2004-2009)
  4. Royal Society Dorothy Hodgkin Fellowship: Token Passing Networks and Pattern Classes of Permutations Huczynska, S. (2004-2008)
  5. EPSRC: Applications of Automata and Languages in the Theory of Pattern Classes of Permutations. Ruskuc, N, Linton, SA, Robertson, EF. (2004-2007)
  6. EPSRC: Refinement-Driven Transformation for Effective Automated Constraint Modelling. Miguel, I. & Gent, IP. (2006-2009)
  7. EPSRC: Symmetry and Search Network. Linton, SA, Smith, BM, Melham, TF, Gent, IP, Fox, M, Kelsey, TW. (2004-2007)
  8. EPSRC: Symmetry and Inference, Linton, SA, and Gent, IP. (2003-2006)
  9. EPSRC/Microsoft: CASE for New Academics Grant, Miguel, I. (2006-2009)
  10. EPSRC: Academic Fellowship. Mitchell, J. (2005-2010)
  11. Nuffield: Backtrack Search in Matrix Groups, Roney-Dougal, CM (2007-2008)
  12. EPSRC: Proof Theory and Constraint Satisfaction. Gent, IP. & Dykhoff, R. (2007)
  13. EPSRC: Watched Literals and Learning for Constraint Programming. Gent, IP & Miguel, IJ (2007-2010)

Research Visits

Steve Linton: Lisbon; Eindhoven; Waterloo, Canada
Alexander Konovalov: Waterloo,Canada
Nik Ruskuc: Dunedin, New Zealand; Sydney, Australia
Tom Kelsey: Montevideo, Uruguay; Birmingham; Imperial College, London
James Mitchell: Centre of Algebra, University of Lisbon; Leeds; Technical University of Wroclaw, Poland
Ian Gent: Oxford; Birmingham; Imperial College, London
Sophie Huczynska: Pennsylvania State University
Max Neunhoffer: Aberdeen University
Colva Roney Dougal: Aachen


Michael Atkinson, Otago
Miklos Bona, Florida
Victor Bovdi, Debrecen
John Bray, Birmingham
U Darji, Louisville
Luis Descalco, Aveiro
Bob Gray, Leeds
Youssef Hamadi, Microsoft Research, Cambridge
George Havas, Queensland
Derek Holt, Warwick
Mark Kambites, Manchester
Elizabeth Kimber
Frank Lubeck, Aachen
Ayan Mahalanobis, Stevens Institute, New Jersey
Scott Murray, Sydney
Yohei Negi, UWA
Max Neunhoffer, Aachen
Justin Pearson, Uppsala
Richard Parker, Cambridge
Bruce Sagan, Michigan State
Akos Seress, Columbus
Mark Stather, Warwick
Rick Thomas, Leicester
Alexei Vernitski, Essex
Julian West, Victoria
Luke Woodward, Oxford
Mickael Gastineau, Institut de Mecanique, Celeste, Paris
Stuart Chalmers, Aberdeen
Standa Zivny, Oxford
Sergey Kitaev, Reykjavik
Einar Steingrimsson, Reykjavik
Robert Brignall, Bristol
Lucas Bordeaux, Microsoft Cambridge
Patrick Prosser, Glasgow
Chris Unsworth, Glasgow
Barbara Smith, Leeds
Karen Petrie, Oxford
Gabriel Landini, Birmingham
David Randall, Birmingham
Chris Jefferson, Oxford

Conferences Organised

International Symmetry Conference: 14th-17th January, 2007. Edinburgh, UK.

Postgraduate Combinatorial Conference 2007: 6th-8th June, 2007. St Andrews, UK.

Permutation Patterns 2007: 11th-15th June, 2007. St Andrews, UK.

Advanced GAP Workshop: 11th-15th September 2007. Braunschweig, Germany.


  1. M. H. Albert, S. A. Linton and N. Ruskuc. On the permutational power of token passing networks Theoretical Computer Science (to appear), 2007.
  2. B. Assmann and B. Eick Testing polycyclicity of finitely generated rational matrix groups Mathematics of Computation 76, 1669-1682, 2007.
  3. R. A. Borzi, S. A. Grigera, J. Farrell, R.S. Perry, S. Lister, S. L. Lee, D. A. Tennant, Y. Maeno and A. P. Mackenzie Formation of a Nematic Fluid at High Fields in Sr3Ru2O7 Science 315, 214, 2007.
  4. J. D. Bradley and P. E. Holmes Improved bounds for the spread of sporadic groups The London Mathematical Society Journal of Computation and Mathematics 10, 132-140, 2007.
  5. R. Brignall, S. Huczynska and V. Vatter Simple permutations and algebraic generating functions Journal of Combinatorial Theory Series A (to appear), 2007.
  6. R. Brignall, N. Ruskuc and V. Vatter Simple permutations: decidability and unavoidable structures Theoretical Computer Science (to appear), 2007.
  7. J. R. Britnell, A. Evseev, R. M. Guralnick, P. E. Holmes and A. Maroti. Sets of elements that pairwise generate a linear group Journal of Combinatorial Theory Series A (to appear), 2007.
  8. F. Brunk, and N. Ruskuc  Largest Intersecting Families of Almost Linear Posets submitted.
  9. A. J. Cain. Malcev presentations for subsemigroups of groups – a survey In C. M. Campbell, M. R. Quick, E. F. Robertson, G. C. Smith (eds), Groups St Andrews 2005 Volume I, no. 339 in London Mathematical Society Lecture Notes Series, Cambridge University Press, 256-268, 2007.
  10. A. J. Cain. Malcev presentations for subsemigroups of direct products of coherent groups Journal of Pure and Applied Algebra (to appear), 2007.
  11. A.J. Cain, E.F. Robertson, N. Ruskuc Cancellative and Malcev presentations for finite Rees index subsemigroups and extensions Journal of the Australian Mathematical Society (to appear), 2007.
  12. C. M. Campbell, M. R. Quick, E. F. Robertson and G. C. Smith (eds.) Groups St Andrews 2005, Volume ILondon Mathematical Society Lecture Notes Series, Cambridge University Press, Cambridge 2007.
  13. C. M. Campbell, M. R. Quick, E. F. Robertson and G. C. Smith (eds.) Groups St Andrews 2005, Volume IILondon Mathematical Society Lecture Notes Series, Cambridge University Press, Cambridge 2007.
  14. C. A. Carvalho, N. Ruskuc Finite presentability of Bruck-Reilly extensions of semilattices Communications in Algebra (to appear), 2007.
  15. C. A. Carvalho, N. Ruskuc On finite presentability of Bruck-Reilly extensions of a monoid endomorphism and its powers Algebra Colloquium (to appear), 2007.
  16. C. A. Carvalho and N. Ruskuc. A finitely presented monoid with a non-finitely generated group of units Archiv der Mathematik (to appear), 2007.
  17. L. Descalco and N. Ruskuc Properties of the subsemigroups of the bicyclic monoid Czechoslovak Mathematical Journal (to appear), 2007.
  18. Falconer, K.J. and O’Connor, J.J. Symmetry and enumeration of self-similar fractals Bull. London Math. Soc., 39 (2007), 272-282.
  19. A.M. Frisch, M. Grum, C. Jefferson, B. Martinez-Hernandez, I. Miguel The Design of Essence: A Constraint Language for Specifying Combinatorial Problems Proceedings of the Twentieth International Joint Conference on Artificial Intelligence, 80-87, 2007.
  20. P. Gallagher, N. Ruskuc. On finite generation and presentability of Schutzenberger products Journal of the Australian Mathematical Society (to appear), 2007.
  21. I. P. Gent, C. Jefferson, I. Miguel, P. Nightingale. Data Structures for Generalised Arc Consistency for Extensional Constraints Proceedings of the Twenty Second Conference on Artificial Intelligence, 191-197, 2007.
  22. I. P. Gent, T. W. Kelsey, S. A. Linton, J. Pearson, C. M. Roney-Dougal. Groupoids and Conditional SymmetryProceedings of the 13th International Conference on Principles and Practice of Constraint Programming, 2007.
  23. I. P. Gent, P. Nightingale, A. Rowley, K. Stergiou. Solving Quantified Constraint Satisfaction Problems Artificial Intelligence (to appear), 2007.
  24. I. P. Gent, I. Miguel, A. Rendl. Tailoring Solver-independent Constraint Models: A Case Study with Essence’ and Minion Proceedings of the Seventh International Symposium on Abstraction, Reformulation and Approximation (SARA), 184-199, 2007.
  25. I. P. Gent, C. Jefferson, T. Kelsey, I. Lynce, I. Miguel, P. Nightingale, B. M. Smith. Search in the Patience Game “Black Hole” AI Communications 20(3), 2007.
  26. Gray, R., Ruskuc, N. Generators and relations for subsemigroups via boundaries in Cayley graphs submitted.
  27. A. Grayland, I. Miguel, C. Roney-Dougal. Minimal Ordering Constraints for some Families of Variable Symmetries Proceedings of the 7th International Workshop on Symmetry and Constraint Satisfaction Problems (to appear), 2007.
  28. K. Hammond, A. Al Zain, P. Trinder, S. A. Linton, M. Costanti. SymGrid-Par: Designing a Framework for Executing Computational Algebra Systems on Computational Grids International Conference on Computational Science, 2007.
  29. S. Huczynska, N. Ruskuc. Pattern classes of permutations via bijections between linearly ordered sets European Journal of Combinatorics (to appear), 2007.
  30. C. Jefferson, T. W. Kelsey, S. A. Linton, K. Petrie. GAPLex: Generalised Static Symmetry Breaking In F. Benhamou, N. Jussien, B. O’Sullivan (eds), Trends in Constraint Programming, ISTE, 191-205, 2007.
  31. T. W. Kelsey. Los efectos de la radioterapia sobre el ovario y el utero. La opinion de los expertos Actualidades y controversias en ginecologia 36(8), 20-23, 2007.
  32. T. W. Kelsey. The Automated Calculation of Human Ovarian Reserve 9th Argentine Symposium on Artificial Intelligence, 151-162, 2007.
  33. T. W. Kelsey, S. Brett, W. H. B. Wallace, M. Rajkhowa. Does 3D ultrasound measurement improve the assessment of ovarian volume? Proceedings of the 23rd Annual Meeting of the European Society of Human Reproduction and Embryology. Human Reproduction 22(1), 23-25, 2007.
  34. U. Leonhardt. Invisibility Cup. Nature Photonics 1, 207-208, 2007.
  35. U. Leonhardt, T. G. Philbin. Quantum optics of spatial transformation media Journal of Optics A 9, S289-S293, 2007.
  36. U. Leonhardt, T. G. Philbin. Quantum levitation by left-handed metamaterials New Journal of Physics 9, 254, 2007.
  37. S. A. Linton, B. Assmann. Using the Mal’cev Correspondence for Collection in Polycyclic Groups Journal of Algebra 316(2), 828-848, 2007.
  38. J. D. Mitchell, Y. Peresse, M. R. Quick. Sequences of Functions as Compositions Quarterly Journal of Mathematics 58(1), 71-79, 2007.
  39. Murray, S.H. and Roney-Dougal, C.M. The spinor norm and homomorphism algorithms for classical groupsSubmitted.
  40. M. R. Quick. Maximal Complements in Finite Groups Communications in Algebra 35(4), 1263-1273, 2007.
  41. M. R. Quick. Groups with Virtually Abelian Proper Quotients Journal of the London Mathematical Society 75(3), 597-609, 2007.
  42. V. Vatter. Enumeration schemes for restricted permutations Combinatorics, Probability and Computing (to appear), 2007.
  43. V. Vatter. Reconstructing compositions Discrete Mathematics (to appear), 2007.

CIRCA Preprints

Tom Kelsey Efectos de la Radioterapia Sobre el Ovario y el Utero
Victor Bovdi, Alexander Konovalov and Steve Linton Torsion Units in Integral Group Ring of the Mathieu Simple Group M22
Alexander KonovalovWreath Products in Modular Group Algebras of some Finite 2-Groups
Ian P Gent, Tom Kelsey, Steve Linton, Justin Pearson and Colva M Roney-Dougal Groupoids and Conditional Symmetry
Steve Linton and Alexander Konovalov Symbolic Computation Software Composability Protocol (also known as Protocal X) Specification
Tom Kelsey The Automated Calculation of Human Ovarian Reserve
Victor Bovdi, Eric Jespers and Alexander Konovalov Torsion Units in Integral Groups Rings of Janko Simple Groups
Victor Maltcev On a New Approach to the Dual Symmetric Inverse Monoid I*X
Ganna Kudryavtseva and Victor Maltcev Presentation for the Partial Dual Inverse Symmetric Monoid
Volodymyr Mazorchuk and Victor Maltcev Presentation of the Singular Part of the Brauer Monoid
J. Araujo, P.V. Bunau and J.D. Mitchell Computing Automorphisms of Semigroups
M.H. Albert and S.A. Linton Growing at Perfect Speed
Steve Linton and Alexander Konovalov Symbolic Computation Software Composibility Protocol (SCSCP) Specification Version 1.0
S. Brett, T.W.Kelsey, W.H.B. Wallace and M. Rajkhowa Does 3D Ultrasound Measurement Improve the Assessment of Ovarian Volume?