Lin Chaoxi's original guess was that, because of the emergence of a quasi-polynomial algorithm for exact graph isomorphism, after proving that the exact graph isomorphism problem belongs to an NPC problem, Professor Zeng would become the one who left a significant mark in the history of mathematics. So he took out the research results of Lao Lin many years ago, improved them and published them.

but……

But if the proof given by Lao Lin many years ago was wrong, then this paper would not have been published at all. And it really doesn’t matter how this paper came about or whether Professor Feng committed academic misconduct in the process of writing this paper.

All because it's wrong.

"How could this happen?" Lin Chaoxi heard her own breathing, and she suppressed her voice and tried her best to stay calm, but she knew that she seemed to be standing in the rain, her eardrums were buzzing, and she was drenched by the heavy rain.

After a while, she was able to continue, but she still couldn't stop trembling slightly, "Then do you know who wrote the letter?"

"I don't know." Pei Zhi said softly, "Do you know him?"

"I..." Lin Zhaoxi covered his lips, "I just find it very strange. Since the writer of the letter realized that there was a problem with the proof, why didn't he publish it in an academic forum, but wrote a private letter to Professor Zeng to relay it on his behalf?"

"It's not surprising, because he is a very serious person. The publication of all academic views should not be casual, it needs peer review, and Professor Zeng is a very suitable candidate." Pei Zhi paused, "More importantly, for mathematicians, direction is very important, and the wrong direction will affect many people's academic research. If he spoke about this matter, it would most likely fall on deaf ears, and it may take some time for people to discover the problem. He said in the letter that he didn't want others to waste their academic lives on the wrong issues like him."

I don't want others to waste their academic life on the wrong problems like him.

This sentence is too light and too heavy.

"He must have studied it for a long time, but he was wrong. What a pity." Lin Chaoxi said it word by word, feeling sad and embarrassed.

"From the perspective of consequence theory, a false proof is really meaningless." Pei Zhi seemed to be urged by someone on the other end of the phone, but he still spoke slowly and steadily: "But this is mathematics. All attempts at the unknown are very precious."

"Yeah." Her hands were shaking, and she had used up all her strength to say this.

At this moment, she heard the gymnasium broadcast in the background: "Next, please invite the outstanding graduate representative, Pei Zhi from the Department of Mathematics, to come to the stage to give a speech."

It was a perfect interruption. She said reluctantly, "Go ahead and talk. I'll be in time later and will send you off at the airport. We can talk then."

"The letter also proposed a new approach to error proof." Pei Zhixiang walked into the meeting room from a quiet place again, "But he said that his body may no longer be able to continue the research. When he is sure that he can no longer continue, he will pack up all the drafts and send them to Professor Zeng. I am very sorry."

The call was hung up.

Lin Chaoxi stood in front of the window of Lao Lin's office, his eyes fixed on the cardboard box under the desk, and he felt as if he was shrouded in a great emptiness.

Everything around is fading, and no matter how bright the sun is, there is no hope.

Before hearing the last sentence, she still had such an idea. Could it be that the person who wrote the letter was not Lao Lin, and Lao Lin only reported Professor Zeng's academic misconduct? She still had a chance to do something for Lao Lin?

But when Pei Zhi said, "Due to health reasons, I am unable to continue my research," she probably understood that there would be no one else and she might not have a chance.

On his desk lies the elementary school math problems that Lao Lin had done with all his effort. His self-evaluation is crystal clear—his long-term memory is intact and he remembers the formulas very clearly, but he has difficulty using them.

In fact, Lao Lin was very clear-headed. He thought about protesting, so he wrote a letter to the editorial department. But after realizing that there were mistakes in the paper and he had no way to do anything about it, he chose the best way to deal with it.

Because of his illness, he had to deal with the problem as quickly as possible, so Lao Wang said, "Professor Zeng clearly opposed Professor Feng's thesis."

Because of his illness, he had even packed up his manuscripts and was waiting to mail them out after leaving the company. Then he resigned from the company and happily went to the noodle shop with her to eat noodles.

He always cares about the impact his mistakes may have on others. But obviously, when he realizes that he has made a mistake, it is also a time for him to have new inspiration and self-breakthrough.

But because of the disease.

Lin Chaoxi couldn't help but squat down beside the desk. She felt that she should burst into tears, but she didn't cry.

It turns out that when you feel extremely regretful, it is just like what is written in the novel, it feels like something has dug a huge hole in your body, as if the wind is blowing through but you can't catch anything.

Lao Lin has seen it clearly: fate is the most cruel mountain that no one can cross.

In front of this mountain, everyone is equal and nothing is a big deal.

In front of him was the cardboard box packed by Lao Lin. Lin Chaoxi almost unconsciously took out the things inside one by one, wanting to see if there were any drafts related to the diagram isomorphism or NPC problem.

If it were a few months ago, she probably wouldn't have understood any of this, but now she can roughly understand it.

After flipping through the draft papers one by one, she finally realized that this was indeed content related to graph isomorphism.

She roughly understood the annotations that Lao Lin had made on the edge of the manuscript. She knew where the errors in the argument were, what new lines to choose, and some possible explorations. Lao Lin had written them very clearly.

The sunlight completely enveloped her, and the drafts, new and old, glowed brightly.

She probably still feels very proud.

For so many years, her father has been doing the work he truly loves, quietly and for his own amusement, but generally with great concentration and seriousness.

But precisely because he realized this so deeply, Lin Chaoxi found it even more difficult to accept.

After so many years of silent dedication, he finally succumbed to the inevitable fate. The three words "Lin Zhaosheng" will not appear in the history of mathematics. He will truly disappear in the dust, and no one will remember him except her.

Is the result really unimportant?

After flipping through the last page of manuscript, Lin Chaoxi took a deep breath.

At the bottom of the carton were several books that Lao Lin had taken away.

One is "Introduction to Calculus and Mathematical Analysis", the other is "Approximation Algorithms for NP-hard Problems" and the other is "Daily Practice of Mathematical Olympiad for Primary School Students".

Those books were very old. She flipped through them one by one. The blank spaces were filled with Lao Lin's annotations. Lao Lin's habits had never changed over the years.

Finally, Lin Chaoxi picked up the book "Daily Practice of Elementary School Mathematical Olympiad", which had a childish color illustration on the cover and the three words "Lin Chaoxi" written crookedly.

Lin Chaoxi was stunned for a moment before she realized that it was the teaching material that her teacher used to teach her Olympiad mathematics when she was in elementary school.

After opening it, there were indeed a lot of her childish handwriting inside. Lao Lin never corrected her answers, but he would occasionally write something interesting after she finished the questions.

Sometimes it was a "turtle", sometimes he drew a few ducks. Lin Chaoxi could no longer remember the specific circumstances when Lao Lin wrote these things, but she was very sure that these were things that happened in the real world.

Because in the distant parallel space, she had never done such a problem, let alone had such a memory.

It was also at that moment that Lin Chaoxi had a clear feeling that he existed in two different worlds.

At that moment, a strange thought suddenly floated into her mind for no reason, like a dragonfly skimming the water, but it left a deep impression.

She couldn't help but glance at the snowflakes of manuscript paper on the ground again. This was the content in this world where Lao Lin had made a breakthrough but was unable to continue.

So what about in that world?

What about that world where Alzheimer may not exist, and where Lao Lin and she may be living well now, even though they were once separated?

Although it seems like a fantasy, can she bring the unfinished work of Lao Lin in this world to the Lao Lin in that world who still has strength to spare?

Obviously, paper materials cannot go to parallel time and space, so she must understand and remember all the contents as much as possible and then take them away.

Since June 30th was circled in red by Lao Lin, what does it matter if it is proven to be wrong now? What does it matter if academic misconduct is no longer meaningful?

The deadline is the deadline. Today isn’t over yet, is it?

How can the result not be important? The result is very important!

At this moment, Lin Chaoxi knew her goal very clearly, it was very clear.

Whether she can succeed or not, she wants to try.

After that, Lin Chaoxi calmed down quickly. The first thing she did was to get up and lock the door of Lao Lin's office.

She sat down at Lao Lin's desk again, opened her email, and downloaded the thesis materials she had packed at the library of Yongchuan University this afternoon.

There is a printer in the office, and the paper printing process was very smooth.

She picked up a pen and paper and the printed paper, sat on the sofa chair where Lao Lin usually sat, and carefully read the first line of the abstract.

This paper has been semi-officially published by Professor Feng, with a complete discussion process and proof ideas. The first thing she needs to do is to understand Professor Feng's erroneous proof, and there is no better textbook than this paper.

The steam of tea was far away, and Lin Chaoxi was very focused. However, the thesis was written in English, and even though she was good at English, there were still many things she couldn't understand. So she read it carefully for the first time and then looked up. An hour had passed.

There were a lot of things on the paper that she had circled in red pen, so densely packed, she calmed herself down and read it a second time.

Time passed by, and during this time Manager Zhang knocked on the door.

Lin Chaoxi shouted, "No, lend it to me for an afternoon," and the middle-aged man was sent away.

The third time, she put the paper down and walked to Lao Lin's packed box, spreading out all the drafts.

The snow-white manuscript paper covered the ground. She knelt on the ground and sorted it out in logical order.

All the contents were divided into three piles. Starting from the preliminary proofs, she opened the first sheet of manuscript paper that Lao Lin had sorted out.

In general, the number of drafts was huge, and her own mathematical ability was not enough to fully understand Lao Lin's ideas, so she found it very difficult to read.

She really wished she was Pei Zhi, so that she could clearly copy all the contents in her mind at a glance.

But it was obvious that she was not Pei Zhi.

She could only remember as much as possible while trying to understand. If she couldn't understand, she had to recite it by heart.

Under time pressure, she had never experienced such a painful memory process. Faced with those processes that were completely unfamiliar to her, she could only write down each symbol bit by bit, put down the paper, restore it in her mind, and then look at it again.

This cycle repeats itself

She hated herself for not learning a little more before, which might have speeded up her process.

But at the same time, she felt sincerely fortunate.

Fortunately, she had chosen to embark on a completely different path in life. She had studied hard and never slacked off, so that when faced with the vast amount of manuscript paper in front of her, she still had the courage and ability to continue.

As the sun set, her phone kept flashing.

Class monitor - Damn, you really missed the graduation ceremony completely. When will you come to get your diploma?

Lu Zhihao - Why haven't you come yet? Did you and Pei Zhi tell each other to go directly to the airport?

Hanajuan——I’ve arrived at the airport, but you haven’t come yet. Are you more famous than me?

Looking up again, the sky was filled with a vast expanse of brilliant sunset glow, as gorgeous as fire.

At this moment, the dark screen lit up again.

Pei Zhi——Is the problem solved?

Looking at the name on the phone, Lin Chaoxi was stunned for a moment, and then realized that she probably couldn't make it to the airport.

All the confession processes she had thought of became meaningless. The sky was not bright today, and it turned out that the goodbye outside the corridor of the classroom that day was not a farewell.

The long life between them may begin from this moment, and they will never meet again.

Lin Chaoxi put down the last page of manuscript and stood up.

The setting sun outside the window was as red as blood, and all the scenery in the city was dyed with a magnificent orange-red halo.

She walked to the window, dialed Lao Lin's number, pressed the speakerphone button, and placed the phone on the windowsill.

She took a deep breath, picked up a pen, and wrote an "e" on the "Elementary School Mathematical Olympiad Daily Exercises" with her name on it.

The call was connected.

"Comrade Lao Lin, I have a question." Lin Chaoxi freed his other hand and opened the window bolt. "In this long and beautiful life, have you found what you really want to do, and have you never regretted your original choice for a moment?"

——“=mc”

The setting sun was scorching outside the window, and on the phone was a new message from Lu Zhihao.

Lu Zhihao——We have arrived at the airport. When will you come? And Pei Zhi...

The window was open, and the summer wind rushed in, blowing the manuscript papers all over the floor.

"Of course." said Lao Lin.

——“^2.”