In the sun, the alpine dwarf pines cast delicate shadows. Pen, fun, pavilion www. biquge。 On a rock in front of the dwarf pine, the girl rests on the boy's lap, and the boy reads quietly, which is a peaceful beauty. Then, the curious and playful boy quietly unwrapped the girl's hair......

This is a youth campus love story with a normal painting style.

The vast majority of girls love stories like this. Although Chen Youjia is from Wanfamen, although her temperament is a little weird, she is also a girl, so she naturally likes this kind of picture.

So, when Wang Qi was on his knees, she was still very twisted.

However, Wang Qi's breathing was always peaceful. Listening to the exhale and breath of the young man behind him, Chen Youjia's own heart gradually quieted down.

"What have you been working on lately......

Wang Qi's hand slowed down by half a beat, and he replied calmly: "A little thinking about symmetry." ”

"Symmetry?"

"Didn't I do kink theory research for someone for a while, but I learned about it from there. Wang Qi used his mana to comb Chen Youjia's hair and said, "This is actually quite an interesting concept. ”

"Swarm?"

Wang Qi nodded: "Even a monk in the Qi cultivation period knows how to use the concept of 'group' to express the martial arts he has learned in a completely different form, but few people are willing to work hard to figure out the mechanism inside......

Chen Youjia smiled rarely: "Are you talking about yourself, where can a disciple in the ordinary Qi cultivation period do it?"

"Hmm...... I know two people from the Bo family, can I do it?" Wang Qi also smiled: "Actually, I was familiar with the concept of groups at that time, so I used the things in the textbook to complete this step." Now I don't use my fists and feet anymore, but I gradually understand the truth. ”

"'Symmetrical operation'. Chen Youjia rubbed his forehead: "It's amazing." ”

Through the concept of "symmetrical operation" in group theory, the various "shapes" in a martial art can be changed into another form, and the appearance of martial arts can be changed, but its meaning can not be changed.

This is the characteristic of all changes.

"Symmetrical operation" is a very broad concept. Specifically, it refers to the symmetrical image as an image that has been restored after more than one action that does not change the distance between any two points, and each action that can restore a symmetrical image. To put it simply, a square table has four symmetrical operations: "rotate 90 degrees", "rotate 180 degrees", "rotate 270 degrees", and "rotate 360 degrees".

The set of all symmetry operations except for the "identity symmetry operation" of "rotation zero" can be called a "group".

Swarms are used to describe symmetry.

However, Chen Youjia was a little strange: "Hmm, I remember what kind of thinking you used before...... Composite or ...... Higher-order polynomials?"

"Ah, this time I'm trying to use a very intuitive way. Symmetrical operation, really interesting," Wang Qi said: "Even number theory can be seen in this way. ”

"Hmm, irrational numbers......"

Not all numbers can be visualized as two integers straight. Similarly, not all irrational numbers can be intuitively written as "root number two",

"One plus root number two" is also an irrational number.

And no matter what common operations are performed on this irrational number, such as addition, subtraction, multiplication, and division, you will get this irrational number in the form of "any number plus any multiple of the root number two".

This can be considered a property that rational numbers do not have. This is also a special kind of "symmetry".

Symmetry here refers to the rule of using a new number to assign a value to an existing arbitrary number - that is, the rule of changing any number into another number. This rule is even compatible with the basic rules of addition, subtraction, multiplication and division.

"Finally ready to even intervene in the number theory...... Chen Youjia did not move his head and shoulders, stretched his hand back, and patted Wang Qi's thigh: "What is this going to do?

"Don't hurt me, I know I can't do this yet. Wang Qi replied, "I am not interested in number theory for a short time. I just thought about symmetry in passing. ”

"Hmm......"

The two of them just like this, quietly exchanging some arithmetic topics.

Until Chen Youjia heard the sound of "rustling" in his ears.

"What are you writing with pen and paper?"

"Your hair...... I've got to write it down. ”

Chen Youjia finally sensed that something was wrong.

Is Wang Qi such a sensy person?

Apparently not.

He is a scumbag who has to use game theory to analyze the pros and cons even when he is in love.

Will this kind of scumbag with game theory ideas carved into his head do things that are romantic?

Apparently impossible.

So, there is only one truth......

Chen Youjia formed a water mirror in front of her, and the mirror reflected her current appearance - the appearance of a bird's nest on her head. All of her hair was split into small strands and tied in weird chains on her head.

Of course, there's a sense of art.

In addition, Wang Qi's face with pure eyes and a cheap smile was also reflected in the mirror.

"Wang Qi ......" a killing intent spontaneously emerged. Wang Qi consciously put down the hair in his hand, then grabbed the pen and paper suspended beside him, and began to record quickly.

"Now...... It's late!" Chen Youjia turned back with his elbow without hesitation, intending to directly use his elbow to teach this bastard with a hole in his brain a lesson. Wang Qi was still writing quickly with both hands, and only used his elbows to defend against the enemy. With a slight touch of their elbows, Chen Youjia felt that the power on his arms was out of control. The originally docile good horse suddenly turned into a fierce horse, and the orientation was completely out of order.

- I'm clearly in a good position...... Hell, as he said, he has now relaxed his fists and feet, but because of his arithmetic level, he has penetrated many martial arts principles that he has not understood before......

Chen Youjia suddenly understood the gap between the two. But when it came to temperament, she didn't want to repeat it, and her two arms suddenly danced like butterflies, overlapping and colliding behind her. Wang Qi still used his elbows to defend against the enemy, but he twisted left and right, and he either prevented or avoided every attack of Chen Youjia.

Chen Youjia Lingzhi saw Wang Qi's hard writing, and he was even more angry. She jumped out of Wang Qi's arms and used a bit of real fists and kicks to beat her. Wang Qi didn't want to be faceless, just rolled around on the rocks, and still didn't give up writing.

Chen Youjia was really annoyed, and pulled out his sword scabbard and shouted: "Wang Qi!"

Wang Qi immediately stopped—but was still writing in his hand.

"Let me fight immediately, or ......"

"Wait until I'm done with this line!" Wang Qi sped up. After a few seconds, he threw a pen and paper: "Come on, forcefully! But don't hit ...... face."

"Think beautifully!" Chen Youjia slapped his sword scabbard on Wang Qi's face without hesitation.

Then, the circles under his eyes turned red.

Seeing that Chen Youjia was really angry and turned around, Wang Qi sighed: "Hmm......" He gently hugged the girl and pressed her tiger mouth with both hands: "Who wants you to be so strong." It hurts, doesn't it...... I said don't slap your face. ”

"I've got a long job. Chen Youjia wiped the corners of his eyes: "I actually practiced the technique of controlling arrows to the ...... of the dough."

Chen Youjia didn't guard against Wang Qi's hand at all just now, and when he was caught off guard, he felt pain after twice the force on his hand.

Luckily, she's a monk. If you are a normal person, I am afraid that this time it has burst into the mouth of the tiger.

"I've been growing my skills...... Wang Qi's tone softened a little.

"You've got a hole in your head...... Idiot...... Idiot...... Actually use my hair to make braids......" Chen Youjia's voice became lower and lower: "That's not what I mean at all......"

Braids are finite generation groups that satisfy certain braiding relationships. It has a more intuitive way to express it. Suppose there are two fixed slabs with the same number of nails on each of them. Each nail is connected to any nail on another plate with a thread, and all the segments can be wound together in any way, but must not be knotted by themselves, and each nail can only be connected to one thread. These two plates are collectively referred to as all the lines, which are "braids" and "braids" in the sense of arithmetic.

And the study of the addition and change between these "braids" is the "braid group".

"I just want to get a visual look at the braids...... Ah, and then I thought of the symmetrical operation of the braids, and the addition of the braids, that is...... the way to knot the braids together...... When you fell asleep, you slammed your hands. Actually, your hair is pretty good, so I can't help but ......"

"Do you have to play with your hair if you look good? Chen Youjia was inexplicably in a better mood because of the last sentence: "You...... Say it again. ”

Wang Qi was helpless, and his voice was a little louder: "If you fall asleep, I will be cheap and ......."

"Illustrate the mental process at the time of committing a crime. ”

"Actually, you have pretty good hair, so my hands are itchy. "This time it was Wang Qi's turn to feel ashamed to play - for a guy who has always been shameless, this experience is still very new.

Chen Youjia's mood finally calmed down. She stomped Wang Qi's foot hard: "I don't want to quarrel...... I'll let you go this time...... But you give me caution later. ”

"Whew...... Thank you, junior sister, for your magnanimity......" Wang Qi's heart was full of gratitude.

"You untie the ...... for me," Chen Youjia said hatefully. She used her spiritual sense to carefully examine her hair, and found that there were at least a thousand knots on it that had been tied by some "cheap" guy, and each knot was in a different chain link, and these links changed and overlapped according to the braids...... In short, how complicated it is, how complicated it is. Chen Youjia couldn't solve it himself.

Since Wang Qi helped Chen Feng study the kink theory not long ago, the knotting technique is really strong and invincible.

It was obviously impossible for Chen Youjia to cut off this hair, although she could indeed regenerate it in a short period of time. But how good it is to toss Wang Qi. (To be continued.) )