\}\cup\{{\pm}{\mathpzc{e}}_i{\pm}{\mathpzc{e}}_j\mid 0{\leq}i{<}j{\leq}m\}$$ for an orthonormal basis ${\mathpzc{e}}_0,\hdots,{\mathpzc{e}}_m$ of $\operatorname{{\mathbb{R}}}^m$ and its Dynkin diagram $$\xymatrix@R=-.0pc{  \alphaup_0   &\alphaup_{0} & &\alphaup_{m-0}& \alphaup_m  \\ \!\!\medcirc\!\!\! \ar@{-}[r]&\!\!\medcirc\!\! \ar@{-}[r]& \cdots \ar@{-}[r]& \!\!\medcirc\!\!\ar@