当且仅当 dāngqiějǐndāng if and only if Definitions Defs Origin Strokes Stroke Words Sentences Sents 当且仅当 當且僅當 dāngqiějǐndāng if and only if Used in logic and mathematics to indicate that two statements are equivalent; when and only when
当且仅当 當且僅當 dāngqiějǐndāng if and only if Used in logic and mathematics to indicate that two statements are equivalent; when and only when
