Formal mathematical definition
[计] 形式数学定义
🧩 词语组成解析
formal
['fɔ:məl]
adj. （学校教育或培训）正规的;方式上的;礼仪上的;
n. <美>须穿礼服的社交集会;<口>夜礼服;
🗣️ 情景例句
I have one ten-day tour that is still available. It will depart from New York on Dec. 24.
我们一个10天的旅行团还有空位，12月24号离开纽约。
What can it be?
它是什么呢？
He is now satisfied merely to try to stand up, but as soon as he does so a porpoise knocks him flat.
此时的海龟，只要能站起来就满足了，但它刚站起来，就被一只海豚击倒。