- Invited EPSRC-funded speaker to the London Mathematical Society Durham Symposium on Geometric Integration, Durham University, July 13-23, 2000.
- Invited NSF-funded speaker to the AMS-IMS-SIAM Joint Research Conference on ``Symbolic Computation: Solving Equations in Algebra, Geometry and Engineering'', June 11-16, 2000, at Mount Holyoke College, Massachussetts.
- Invited speaker to the CMS/CAIMS Meeting at McMaster University (June, 2000).
- Invited speaker to the Workshop on Computational Algebraic Analysis, Mathe
matical Sciences Research Institute (MSRI), Berkeley, Jan 5-7, 2000.
- Invited speaker to the Winter Meeting of the Canadian Mathematical
Society, Dec 11-13, 1999, Université de Montréal, Montreal.
- Invited speaker to the 1999 International Symposium on
Symbolic and Algebraic Computation, Vancouver, 25-28 July 1999.
- Invited speaker to the meeting Foundations of Computational Mathematics
(FoCM'99), Oxford University, 18-25 July 1999.
- Invited speaker funded by the NSF and CONACYT to the Conference on Gröbner Bases, (February 8-12, 1999, Guaranjuato, Mexico),
organised by Eisenbud, Sturmfels and Gomez-Mont.
- Invited speaker and member to MSRI, Berkeley, Aug'98-Nov'98.
- Invited speaker to the 1997 International Symposium on
Symbolic and Algebraic Computation (Maui).
- Invited speaker to IMACS'97 conference on computer algebra
(Maui).
- Invited speaker to IMACS'96 conference on computer algebra
(Castle Hagenburg, Austria).
- Invited speaker to the 1995 International Symposium on
Symbolic and Algebraic Computation (Concordia, Montreal).
- Invited speaker to IMACS'95 conference on computer algebra
(University of New Mexico).
- Invited speaker to the Workshop on Exterior Systems and
their Applications (Centre de Recherches Mathématiques,
Université de Montréal, 1994).
- Invited speaker to the 1994 meeting of the Canadian
Mathematics Society (University of Alberta, Edmonton).
- Invited speaker to IMACS'94 conference (Georgia
Institute of Technology, Atlanta).
- Invited speaker to the twenty-second AMS-SIAM Summer
Seminar,
*Exploiting Symmetry in Applied and Numerical Analysis*(Colorado State University, 1992). - Invited speaker to the 1992 International Symposium on
Symbolic and Algebraic Computation (University of California, Berkeley,
1992).
- Invited speaker to the course:
*Partial Differential Equations and Group Theory: New Perspectives in computer algebra and engineering sciences*(GMD, Bonn, Germany, 1992). - Invited speaker to the 1991 International Symposium on
Symbolic and Algebraic Computation (Bonn, 1991).
- Invited speaker to the fifth Gregynog Symposium on
differential equations (Gregynog, Wales, 1991).