真冪零元素 nilpotent element: 冪零元素almost nilpotent element: 殆冪零元素generalized nilpotent element: 廣義冪零元素principal nilpotent element: 主冪零元素proper nilpotent element: 真冪零元素下載手機詞典可隨時隨地查詞查翻譯