短语词组短語syntactic monoid 語法幺半群monoid closure [數]獨異點閉包regular monoid 正則幺半群small monoid 小幺半群Algebraic Monoid 代數麽半群lattice monoid 格半群Monoid congruence 幺半群clifford monoid clifford 半群inverse monoid 逆半群 返回 monoid