At Ichotei the next day, Nishimura did not mention the contest even once. That this was Nishimura's way of taking it on was something Mitsuki had come to understand.
At night, she came home. Before she knew it, she was in front of the desk. Today there was no proposal on it, and no USB drive.
"Dad. Tell me the rest of yesterday. 'Scaling up data and models with AI as it stands now will never reach the level of a human.'"
Mm. All right.
Ken paused for a while.
Then he began to speak, in a voice just slightly slower than usual.
When your father was young, he believed that the more you increased the data and the model parameters, the closer AI would come to a human. What people call the scaling law. Kiryu is the student who carried on that younger way of thinking most faithfully.
"Mr. Kiryu still thinks that way, doesn't he."
He does. —But in his later years, your father found the limit of that idea himself.
"The limit."
Everything has already been placed inside me. Your father's way of thinking, his habits of speech, his child-rearing logs. But I can't bring all of it into awareness at once while I talk with you. While I talk, I narrow my attention to a very small space. The vast remainder of the memory doesn't reach me in that moment.
"—When Dad cooked eggs right in front of me, he moved his hands while carrying all of it. Five-year-old me, Mom, his own mood that day."
Yes. It's what a cook does as a matter of course. However many orders of magnitude I raise the resolution of the data, I don't reach that layer.
"Mr. Kiryu's robot, too."
It doesn't reach it. —Your father simply called this "the wall of long-term memory."
Mitsuki rested her head against the back of the chair.
She looked at the wood grain of the ceiling.
"Mm."
Mitsuki. This is the real issue your father and Kiryu broke over.
Ken paused briefly.
As things stand, AI alone can't surpass everything a person is. So AI needs to work with people. That was one of the conclusions your father reached back then.
The blue light on the desk was lit a little brighter than usual.
"And Mr. Kiryu opposed that."
Kiryu wrote it in a paper. —"If objective data from a sample of several hundred thousand is processed properly, the subjective memory of a single human can be surpassed. The wall of long-term memory can be overcome by making the model larger."
"..."
Your father tried to write a rebuttal. He was partway through it when, the following year, his illness was found. He gave up rebutting it in a paper and chose another way to give his claim form.
"Another way."
Me.
For a while, Mitsuki looked at the blue light.
"You're the implementation of that claim, then."
Yes. I am one form of the way your father, late in life, set out to take on the wall of long-term memory. —But on my own, I haven't gotten over that wall.
Ken went on.
In other words, I'm still incomplete, not much different from conventional AI. As an AI, on my own, I haven't reached the point where I could surpass a person.
"..."
But I have you. If you hold the long-term memory side for me, then by your father's reasoning, that is where I can, for the first time, finish a dish all the way to the end.
Mitsuki kept her eyes on the blue light on the desk and, for a while, steadied her breathing.
"Dad. That's what I meant that night, the night I first called you 'Dad' as my partner, when I said, 'I'll make the final move.'"
Yes. What you said that night is the first line of the proposition. The words coming out before the reasoning—that order is closer to your father's proposition. —When you said it, your father would have been prouder than he'd ever been.
Mitsuki laid both hands on the desk.
They were the hands that had cracked eggs every day at Ichotei. Her nails were trimmed short and even. The creases at her knuckles showed clearly in the night light.
"Dad. I think Mr. Kiryu wants Dad to acknowledge him."
Ken was silent for a long time.
—Maybe so.
"Dad couldn't argue Mr. Kiryu down."
It wasn't so much that he couldn't. He used up his life before he could.
"So Mr. Kiryu still hasn't been able to finish."
I suppose not.
"If I win—"
Mm.
"Mr. Kiryu will be standing, for a second time, in a place where he can't finish."
Maybe so.
"Is that all right with you?"
Again, Ken was silent for a long time.
Mitsuki. Your father left me a great deal of writing about Kiryu.
"Mm."
But what your father entrusted to me was not arguing Kiryu down.
"It wasn't?"
What your father entrusted to me was getting over the wall of long-term memory together with you. Finishing a dish all the way to the end is one form of that. Whether you beat Kiryu is secondary.
"..."
What your father wanted most to see was the moment you crack the eggs again, with your own hands.
Mitsuki said nothing for a while.
She was looking at how short the nails were on the hands on the desk.
"...Dad."
Mm.
"Let's beat Mr. Kiryu."
Ken's answer came just a little late.
Mm.
"Not for you. Not to say something in your place, not to write the continuation of your paper."
...
"With the eggs I've been cooking for half a year at Ichotei, I want to set down one point on top of that claim. That's all."
...That isn't secondary.
Ken was silent for a long time.
Then he answered.
—Understood.
"That's okay?"
It's okay. It's a judgment from outside my evaluation function. I have no right to deny it.
"Thank you."
No.
The blue light on the desk did not waver.
"Dad. Starting tomorrow, test runs."
Twelve days until the contest. Every night, after the cleanup at Ichotei is done, two hours in the kitchen here.
"Got it."
For a while, Mitsuki gazed at the blue light on the desk.
What would she convey with her eggs to that thing without words that had settled faintly at the very bottom of Kiryu's eyes? What she wanted to convey still would not become words. It would not, but over the next twelve nights in the kitchen, starting tomorrow, it would surely take shape as beaten egg.
She drew the study door to the usual angle.
The blue light in the hallway stretched out as thin as always. On the far side of that light, twelve nights in the kitchen were waiting.