There will be an algebra seminar on Friday 11 November, given by Matthew Dyer. --------------------------------------------------------------------------- Speaker: Matthew Dyer (University of Notre Dame) Date: Friday 11 November Time: 12:05-12:55pm Venue: Carslaw 175 Title: Groupoids, root systems and weak order Abstract: Several (largely equivalent) points of view for notions of groupoid with root system will be described. They are obtained by abstracting basic properties of Coxeter groups, such as the symmetric groups, with their root systems and weak orders. This talk will focus on examples and on aspects of the theory which generalize defining properties of Coxeter groups, such as the exchange condition and their presentations by braid relations. --------------------------------------------------------------------------- Anne Thomas - anne.thomas@sydney.edu.au Seminar website - http://www.maths.usyd.edu.au/u/AlgebraSeminar/