It has been said that mathematics is the language of God.

Based on the logical deduction of this sentence, it can be concluded that human beings can approach God's thinking when they study mathematics, and use this God's thinking to solve all the problems facing the development of human society.

And that's true.

Although for 90% of the world's people, learning advanced mathematics is a very boring subject that will probably not be used for the rest of their lives.

But in fact, mathematics is the most basic discipline, and countless mathematicians have been indirectly promoting the scientific and technological progress and development of the whole world.

Every mathematical problem that is solved has the potential to lead to technological innovation.

For example, the distribution law of Rosen prime numbers corresponds to the application of computer grid technology.

The Hilbert space equilibrium problem has a direct impact on the in-depth study of quantum physics.

The Navistokes equation, which directly describes the conservation of momentum in viscous incompressible fluids.

......

Poincaré's conjecture is proved, and the shape of the universe can be deduced.

If we prove the NP complete problem, we can conclude whether the rules of mathematics and physics in the universe are unified, and whether there is a unified standard that can simplify all the problems......

Therefore, Lu Yuxin's birthday gift to Wang Yufei can probably be understood as the girl gave Wang Yufei her thoughts on everything in this universe on this extremely important day.

Let's just say that this gift is not heavy!

......

No, it doesn't matter if other people think this gift is heavy or not, Wang Yufei thinks it's OK if it's good.

And I really feel very good and happy.

Not to mention those things that have already been thought about.

Just sorting out these questions in a book with a girl's understanding will help Wang Yufei to think about these topics when he is relaxed, and in Wang Yufei's opinion, there is probably no better gift in this world.

Therefore, in the early morning of Wang Yufei's first birthday after coming to the provincial capital, the two children happily began the collision of mathematical thinking, learning about various mathematical problems until three o'clock in the morning.

......

remembers that Wang Yufei's birthday is of course not only Lu Yuxin.

So the next day, Wang Yufei entered the gift receiving mode.

Guo Jianfeng gave Wang Yufei a new Weihua mobile phone, Han Qian bought him a pair of leather shoes with a particularly loud brand, and Guo Xiaoyi took time to carefully draw a sketch for Wang Yufei.

In addition to his family, the school sent someone to send a cake, and Han Wenle prepared a stack of exercise books and sent it over.

For the students who are lively by nature, they even set up a WeChat group early to celebrate Wang Yufei's birthday.

But today is not the weekend after all, so it is very deserted in the WeChat group during the day.

But it doesn't matter, because Wang Yufei is also very happy during the day.

For example, Wang Yufei, who had a big meal outside and lit a birthday cake, was full of emotion, returned home and began to follow Lu Yuxin into the problem-solving mode.

I have to say that it is a rare relaxation and enjoyment to not have to deal with the messy technical problems on Weihua's side, and to concentrate on immersing yourself in the world of mathematical problems.

In this way, at 9:20 in the evening, after the school's evening self-study, the group became lively.

Because Lu Yuxin pulled Guo Xiaoyi into the group chat, and then Guo Xiaoyi pulled many of Wang Yufei's classmates who were familiar with him on weekdays in the third year of junior high school into the group chat.

The result was a large crowd of more than 80 people.

Don't mention the excitement.

All kinds of birthday wishes keep swiping the screen, and there are many who have been sending red envelopes, and the group is happy and peaceful, like a holiday.

In the end, in order to stop everyone's enthusiasm for sending red envelopes, Wang Yufei, who was in a very comfortable mood, directly sent a big red envelope of 5,000 yuan in the group, and the children finally began to change their focus after grabbing the red envelope.

"Haha, thank you, Mr. Wang. ”

"Super Xueba is mighty!"

"Classmate Wang Yufei, do you want me to call you dad when you send such a big bag?"

"Do you dare to have a little discipline upstairs? Dad, is there anything else?"

"Phew!"

After the meaningless water, serious questions finally began to be asked.

"Excuse me, how did Xueba spend his birthday today? @路余馨, hurry up and come out and say, did you go shopping and eating, let us also envy and envy. ”

"No, we spent a day at home solving math puzzles. ”

Lu Yuxin's rare bubbling answered the classmate's question.

"Ma Dan, I really don't understand the world of Xueba. ”

"So you didn't come to school just to solve problems at home every day?"

"Dizzy, dizzy! What kind of math problem to solve, send it out for us to see!"

......

Well, for this kind of request, Wang Yufei of course decided to meet.

After all, it can stimulate the students' love for mathematics, and at the same time, out of the desire to share their most precious birthday gifts and make everyone jealous, Wang Yufei took out his new mobile phone and posted the question book written by Lu Yuxin himself, page by page, page by page, into a photo and posted it in the group.

accompanied by a sentence: "Do you envy this birthday gift that Yu Xin gave me?"

Then harvest a bunch of question marks.

“？”

"I don't understand!"

"So studying these for a day?"

"Sister Lu is mighty!"

"Actually, I'm like this, I never care about a birthday gift or a birthday gift when talking about a girlfriend. ”

"Really, seeing what the birthday star did on his birthday today, I was so ashamed that I suddenly turned on the 360-degree rotation mode on the bed without dead ends!"

As soon as this sentence was issued, the group suddenly calmed down for three seconds.

Subsequently......

"Ma Dan @ Chen Hansheng, why do you send videos with text?!"

"I'm @ Chen Hansheng, Lao Tzu is disgustingly pregnant by you!"

"Are my brothers in high school all like this?"

"I feel like I've been taken badly!"

"Ask for a video!"

"Ask for Video +1"

"Ask for Video +10086"

Then Lu Yuxin came forward.

"@陈汉生同学, give you the last ten seconds to retract what you just said, otherwise I must find a way to make the picture you just described come true in my life, I don't believe you try. ”

"Try it!"

After typing this sentence quickly, the paragraph just now was removed by a certain child with lightning speed!

"Phew, coward!"

"Don't be cowardly, be tough, we support you!"

"Sister Lu is really mighty!"

"Haha......"

......

There were all kinds of joyful air in the group, and it was noisy until the middle of the night.

It wasn't until almost eleven o'clock in the evening that it finally quieted down.

Then the two of them can finally think quietly about these problems again, and then give ideas and collide ideas.

It's wonderful.

Until twelve o'clock in the night, Lu Qingyun's video was sent on time.

"Well, it's over for your birthday, and we've accumulated a bunch of things today, can we start?"

Lu Yuxin: "?"

I have to say that Lu Qingyun still listens to her daughter's words very much, saying that if you don't bother for a day, you won't bother for a day, and you can't do more or less!