<正>We consider the Korteweg-de Vries (KdV) equation in the form ut+uux+uxxx=0(1) which is a nonlinear hyperbolic equation and has smooth solutions for all the
<正> Let ω be the element of maximal length in a finite irreducible Coxetersystem(W,S).In the present paper,we get the length of ω when(W,S)is of typeA_n B_n/