In fact once the symmetry is specified, and quark-lepton charges are given, everything else is fixed: in particular what possible force acting between them follows inevitably.

• 事实上，当某种对称性被特别指定时，夸克和轻子的荷即被指定，所有其它的一切均被确定了：特别是所有它们之间可能的力也被完全确定了。