The salted fish life of the door-to-door son-in-law

Chapter 925 I'm Happy

"Then listen carefully. My guess is that any even number greater than two can be written as the sum of two prime numbers." After speaking, Liu Zhicheng made a gesture of invitation.

Even in Liu Zhicheng's previous lives, no one could fully prove this conjecture. With the level of mathematics in this world, it is probably not enough.

Sure enough, after hearing this, Radhiskov was stunned. Firstly, he didn't expect that this kid could really come up with a conjecture, and secondly, he really couldn't prove it.

For a long time, Ragiskov stood there in a daze, not knowing what to do. It was embarrassing, but Ragiskov was still stubborn, and said to Liu Zhicheng: "You can prove my conjecture, It's just a coincidence, there is a kind of you who are finding a way to prove it, as long as you can use another way, I can also prove your conjecture."

Liu Zhicheng smiled, and said to Radhiskov: "It seems that you really don't cry when you don't see the coffin, that's okay, I'll let you die happily today, remember what you said just now."

After finishing speaking, Liu Zhicheng didn't care about Radhiskov, but asked the students and teachers below: "Have you memorized everything?"

"It's over." The students and the teacher replied loudly excitedly, because today they finally had their own conjecture, and it also proved that the world-class conjecture was wrong. From today, Huaxia finally appeared in the world-class mathematical conjecture. person's name.

As people engaged in mathematics research, they finally feel proud in the international arena. If anyone dares to say that their country's mathematics is not good, they dare to go back on the spot.

"Come up and wipe the blackboard." Liu Zhicheng pointed to the student who just wiped the blackboard and said.

The student walked up to the podium swiftly and quickly finished wiping the blackboard. When he went down again, he said directly to Liu Zhicheng: "Teacher, don't ask, just ask one word, cool!"

Liu Zhicheng smiled, did not speak, then turned around and started writing on the blackboard again.

Assumption: There is no internal region in the combined region of any number of adjacent regions.

Given areas A and B, and A and B are adjacent, because there is no internal area between A and B, then A and B must intersect in a curve, and the endpoints of the curve are a and b.The two outer curves aAb and aBb enclose adjacent areas A and B into a combined area, which is regarded as X.

Any third region C adjacent to A and B must be adjacent to X. Similarly, C and X only intersect on the curve a1b1, and the endpoints of the resulting curve are a1 and b1.

If a1 and b1 are on one of the curves aAb or aBb at the same time, there are two situations:

1. Area C intersects only one of the areas A and B

2. The combination of region C and one of the regions contains the other region, contradicting the hypothesis.

Therefore, a1 and b1 must be on the two curves aAb and aBb respectively, then the area C must intersect X on the curve a1ab1 or a1bb1, that is, the intersecting curve contains point a or b.

Let the combined area composed of three areas A, B, and C be Y.

Any area D is adjacent to the three areas A, B, and C. As shown in the figure above, D must be adjacent to Y. From the above proof, the intersection curve of D and Y must include at least a, a1, The two points in b1, regardless of the two points, D must contain the third area with one of the two areas of A, B, and C, that is, one of the areas must become an internal area, which is contradictory to the assumption.

That is to say, the first conclusion is that at least one of the four two-by-two adjacent areas belongs to the inner area.

Because the inner area cannot be adjacent to the outer area, there is no outer area E, so that the five areas A, B, C, D, and E are adjacent to each other. (Conclusion [-])

Assume that there is an internal region F such that the five regions A, B, C, D, and F are adjacent to each other.

Because at least one of A, B, C, D, and F is an external area.Taking A as an example, A is an external area, because A is adjacent to the other four areas in pairs, then A must intersect with the four areas in at least one curve.

If A is removed, the curves of the other four areas intersecting A are connected to the outside world, that is, the four areas become external areas, and the four areas are adjacent to each other, which is contrary to conclusion [-].

That is to say, the third conclusion is that there is no internal region F, so that the five regions A, B, C, D, and F are adjacent to each other.

Because in the plane, except for the internal area, it is an external area, so conclusion [-] can be obtained through conclusion [-] and conclusion [-], that is, there is no area G, so that the five areas A, B, C, D, and G are adjacent to each other.That is, there are at most four pairwise adjacent regions.

The four-color theorem is proved!

In order to allow students and teachers to read more thoroughly, Liu Zhicheng also specially wrote notes:

Notes:

Internal area: that is, an area that is completely contained in other areas.

Outer region: There is a region where the marginal curve is not contained by any other region.

Combined area: An area that has two or more areas that share common coverage.

After finishing writing, Liu Zhicheng briefly talked about it, because Liu Zhicheng had already let all the students and teachers understand what the four-color conjecture meant, so this time Liu Zhicheng said something briefly, and the students and teachers understood.

Then Liu Zhicheng turned his head to Radhiskov with a smile, and said to Radhiskov: "Come on, I've written the second solution, and it's your turn to prove my conjecture."

After listening to Liu Zhicheng's words, Rajiskov's face turned red. He is a world-class mathematician, but he didn't expect to be trampled under by a little-known little man today, and he was also severely humiliated. a handful.

"What? Can't you prove it? Since you can't prove it, then take your damn apprentice and get out of Huaxia. Huaxia is not a place for clowns like you and your apprentice to run wild!"

Liu Zhicheng stood on the podium, looked at Radhiskov, and said loudly.

After hearing Liu Zhicheng's words, Rajiskov stretched out his trembling hand and pointed at Liu Zhicheng, his lips were trembling with anger, but in the end he didn't say a word, and passed out directly.

Seeing Rajiskov, who was unconscious on the ground and surrounded by his assistants, Liu Zhicheng laughed: "You are still doing mathematics with your psychological quality. I think you are not too young. Go home and play with your grandson. Mathematical research is not for you."

After Liu Zhicheng said this, the students below the podium laughed out loud. Just now they were belittled by Ragiskov, but now Ragiskov was beaten to death by Liu Zhicheng. They were happy See what happens.

"The teacher is right! Let him go home and take care of his grandson!" The students in the audience booed instantly.

Chapter 926 The Entrance Banquet

In the crowd, Will James stood in front of Zhou Xiafei, expressing affectionately to Zhou Xiafei.

And Zhou Xiafei kept a cold face, turning a deaf ear to Will James' confession, if it wasn't for being at school, Zhou Xiafei even had the urge to hit someone.

After Ragiskov fainted from anger, Liu Zhicheng waved to the students and teachers below and left, and then in the crowd, Liu Zhicheng saw Zhou Xiafei standing with a blond hair and blue eyes with a frosty face. in front of foreigners.

It seems that this is the Briton named Wia James that Zhou Xiafei was talking about, so Liu Zhicheng walked towards Zhou Xiafei and patted Will James on the shoulder. The fist hit Will James.

For such a shameless character, Liu Zhicheng was too lazy to explain to him, so Liu Zhicheng simply punched Will James unconscious.

Seeing that Liu Zhicheng made a sudden move and knocked Will James unconscious, Zhou Xiafei said to Liu Zhicheng with some worry: "It doesn't matter if you do this!"

"Let's go, I don't care about him, I guess he's going to get out of Huaxia soon, beating him up is light." Liu Zhicheng said to Zhou Xiafei with a smile.

After finishing speaking, the two left side by side, and tomorrow is the school entrance feast at Zhou Xiafei's house, and they must return to Hangzhou in advance.

After spending the night in Hangzhou, when it was almost noon the next day, Zhou Xiafei drove to pick up Liu Zhicheng. Liu Zhicheng was lying in the Xinxiangshicheng cafe and hadn't woken up yet.

Although Liu Zhicheng had nothing to do during the past six or seven days, he still couldn't sleep comfortably at home, so Liu Zhicheng finally came back, so he needed to get a good night's sleep.

"Okay, don't sleep, wake up." After Zhou Xiafei came to Xinxiangshicheng Cafe, she saw that Liu Zhicheng was still sleeping on the boss's chair, so she came to Liu Zhicheng's side, pulled Liu Zhicheng, Said to Liu Zhicheng.

Opening his sleepy eyes, Liu Zhicheng glanced at Zhou Xiafei and said to Zhou Xiafei, "So early? Didn't it start at noon?"

After Zhou Xiafei rolled her eyes at Liu Zhicheng, she said to Liu Zhicheng, "It's 11:30, the banquet will start in half an hour, you're still asleep."

For Liu Zhicheng, as long as there is nothing wrong, it is normal to sleep until noon. After hearing Zhou Xiafei's complaints, Liu Zhicheng smiled, stood up from the recliner, stretched his waist, and said to Zhou Xiafei : "Let's go to the school entrance banquet."

Zhou Xiafei saw that Liu Zhicheng's eyes even had gum in his eyes, and suddenly said a little speechlessly: "Do you know why my family doesn't treat you very much?"

Liu Zhicheng shook his head.