
The Nil Hecke Ring and Cohomology of G/P for a Kac
... and define a subset W:., of the Weyl group W, by Wk = { U’E W: A + n MJ~ c A +\A$ ). Wk can be characterized as the set of elements of minimal length in the cosets W,w(w E W) (each such coset contains a unique element of minimal length). There is a (@-linear) involution w of g defined (uniquely) by ...
... and define a subset W:., of the Weyl group W, by Wk = { U’E W: A + n MJ~ c A +\A$ ). Wk can be characterized as the set of elements of minimal length in the cosets W,w(w E W) (each such coset contains a unique element of minimal length). There is a (@-linear) involution w of g defined (uniquely) by ...