- #1

naima

Gold Member

- 938

- 54

And I try to understand this. He writes

"Each basic weight is invariant under all but one of the simple Weyl reflections since w_i l_j = l_j for i<>j while w_i l_i = l_i - alpha_i

(alpha_i is

**simple**by definition of simple reflections). Hence th Dynkin indices m' of the reflected weights w_j mu are related to the indices m_i of mu by m'_i = m_i - A_ij m_j"

Could you, please, tell me how to prove that w_i l_j = l_j for i<>j

thanks