A Note on the Root System of an Affine Lie Algebra of type $A_{2l}^{(2)}$

摘要

Let ${rak g} = {rak g}(A)$ be an affine Lie algebra of type $A_{2l}^{(2)} (l>1)$ and $W$ be its Weyl group. In this paper, we find $w in W$ such that $ overset circ o Delta_+ cup {{rac{1}{2}}(lpha_l + delta), {rac{1}{2}}(lpha_l + 3delta) } subset , Delta^+(w)$.