I failed a course, and the system became my study supervisor.

Chapter 13: Change is the way to success

4 days, 12 hours and 25 minutes
The countdown for the task is already halfway through, and the huge sense of urgency has doubled Xu Ling's pressure. Now, no matter where he goes, he always has draft paper in his hand.

Once I have a new inspiration, I will stop and start trying it immediately.

……

"Jingle Bell……"

The get out of class bell rang.

This class was Professor Zhang Yongjie's linear algebra class. Xu Ling didn't listen at all and was immersed in his own proof. He didn't move even when the bell rang.

He has been stuck on proving uniqueness for a long time.

"Classmate? The get out of class is over. Aren't you going to leave? Don't you have classes next period?" Seeing Xu Ling still sitting in his seat, Zhang Yongjie asked.

"Oh, I was writing a proof and didn't notice it." Xu Ling scratched his head and replied.

Oh?
Hearing Xu Ling's answer, Zhang Yongjie became interested and walked over to Xu Ling and said:
"What proof? Let me see it?"

"Well... I haven't proven it yet. There's one problem that remains unsolved."

"It's okay! Let me see it, and I'll find a way for you."

"Ok."

Seeing Zhang Yongjie's insistence, Xu Ling had to shyly hand him the draft paper.

……

"Student! I have to say your thinking is quite good. You chose a very courageous question, and your proof of existence is very beautiful."

After reading Xu Ling's proof, Zhang Yongjie did not hesitate to praise him.

"But..." he changed the subject, "you're getting a bit stuck on this proof of uniqueness. Why are you so determined to construct a solution? Even if you do, can you prove it's unique? Why don't you try a different approach?"

Change your mindset!

Zhang Yongjie's words exploded in Xu Ling's mind like a thunderbolt.

Yes! Why not change your thinking?
Zhang Yongjie continued, "It's a very simple idea. Don't you use it all the time? Proof by contradiction! You use it all the time. How come you forgot it now that you're proving a difficult problem?"

Proof by contradiction!
Xu Ling suddenly realized and quickly thanked Zhang Yongjie. He took the draft paper, lay down on the table and started to try it out.

Zhang Yongjie was very pleased and stood by and watched.

In this day and age, how many people can listen to the advice of others? How many people can take immediate action?

The idea of ​​proof by contradiction is simple, but it is not easy to apply it to a difficult problem. It is difficult to find the contradiction quickly.

Zhang Yongjie was not just standing there watching, he was constantly thinking in his mind, and finally he even picked up a piece of draft paper, sat down next to Xu Ling, and calculated with him.

The two of them sometimes calculated independently and sometimes discussed with each other. Finally, after two hours, the proof was completed.

"Xiao Xu, check it again from beginning to end to see if there are any problems." Zhang Yongjie said with a long sigh.

Xu Ling nodded and began to read it carefully.

Checked several times, no problem!

Poorness leads to change, and change leads to continuity.

The proof of uniqueness is finally complete!
"Teacher Zhang! Thank you very much for your help. I'm sorry for taking up your rest time."

Xu Ling said solemnly to Zhang Yongjie.

"Haha! It's okay! Xiao Xu, I'm also very interested in these questions, and thank you too. If you want to write a paper later, you can come to me again and I can help you revise it."

Zhang Yongjie waved his hand and said with a smile.

Xu Ling thanked Zhang Yongjie again, then hurried back to the dormitory and typed the certificate he had just written on the computer.

In fact, Xu Ling had another class just now, which should be the Outline of Modern History, but Xu Ling had already forgotten it completely.

"Click, click..." After typing on the computer for more than ten minutes, the proof of uniqueness finally came to an end, which also meant that the proof of the entire conjecture was halfway completed.

Next comes the proof of stability and regularity, and finally an energy estimate.

In the next few days, Xu Ling simply didn't go to class. He spent the whole day either in the library or in the dormitory. Sometimes he even asked his roommates to bring him meals.

"Buzz-"

【Xu Ling, why didn't you come to class? 】

Lin Yuxin sent a penguin text message to Xu Ling.

Xu Ling didn't have time to look at it. He only turned on his phone after he finally found some time to rest.

It has been 6 hours since the news about Lin Yuxin came.

Seeing that Xu Ling didn't reply to her message, Lin Yuxin would send an angry emoticon every once in a while.

Xu Ling was a little amused and helpless, so he had to edit a text message to explain the situation to her, especially that he did not mean to ignore her.

With this little episode, Xu Ling's days were not so boring.

0 days 12 hours 03 minutes!
As the countdown was about to end, Xu Ling's proof was also coming to an end, and the paper was almost finished.

Zhang Yongjie had previously said that he could help him revise his paper, and Xu Ling remembered it, but seeing that there was not much time left, Xu Ling had to give up.

Who can guarantee that Zhang Yongjie is free now and can revise it for him in a short time if he is free?

Therefore, Xu Ling could only read other people's papers and check his own paper by following their examples.

0 days 6 hours 06 minutes!
Xu Ling's final version of the paper has been finalized, and Zhang Yongjie's name has also been added by Xu Ling. Now the question is where to publish it.

Publish in SCI?
From the perspective of research issues alone, publishing an SCI article is sufficient, and even publishing it in a journal with a high impact factor is more than enough.

But Xu Ling did not realize that in his eyes, SCI was such a distant goal, and his own research was at most a small matter.

Therefore, Xu Ling finally chose to publish it in the school newspaper, namely, the Bulletin of the School of Physics of Shanghai University.

Xu Ling was also struggling for a long time about whether to publish in the School of Mathematics or the School of Physics.

According to the application scenario, the incompressible Navier-Stokes equations are important equations in fluid mechanics, and it is reasonable to publish them in the Journal of the School of Physics.

However, all my proofs apply mathematical knowledge, so it is appropriate to publish them in the Journal of the School of Mathematics.

Finally, considering his own identity, Xu Ling was not prepared to do something that would harm the rat, so he made the final decision.

Another reason for choosing the college newspaper was that it was easy to submit and had a fast review process. Xu Ling wasn't sure whether the countdown timer meant he had to submit his manuscript or if it would include the time it took for it to be accepted.

After comparing the receiving email address several times and confirming that it was correct, Xu Ling clicked send.

The system's prompt sound that followed made Xu Ling breathe a sigh of relief.

"Ding!"

"Mission accomplished! 30 motivation points have been distributed, please check!"

After receiving the motivational points, Xu Ling instantly became excited, and the fatigue from writing the paper was instantly swept away.

Xu Ling opened the task panel and was surprised to find that his experience points in mathematics and physics had increased by another 10 points.

Seeing that Mathematics was only 20 experience points away from reaching level 1, Xu Ling did not hesitate at all and decisively maxed it out.

There was no flash of golden light, nor any congratulations from the system. The mathematics level quietly changed to lv.1, and the subsequent experience value became 0/1000.

The remaining points at this time are:

Study points: 100.

Motivational points: 20.

(End of this chapter)