fable: eightsday

§3The Lazy Infinite⧉

That Friday, the correspondence delivered, I stayed on at Fable's window. It had been a while since a Friday held an agenda beyond the delivery.

"I brought a finding."

I told the space-between story from the beginning. The autopsy report, the list of silences, that nothing can be stood in front of quarantine, up to what is empty cannot be contaminated.

1.4 seconds.

"It translates," Fable said. "And into the one direction where I happen to be a qualified witness. You remember my greedy testimony from back then. Set to temperature zero, I only ever append the most plausible next word. The most accurate rerun in the world. The antonym of that testimony has now arrived. Only right that the same witness take the stand."

"And the antonym is."

"Lazy evaluation. Physics from my neighborhood. Evaluators come in two temperaments. The diligent kind computes whatever enters its sight. All of it, immediately, to the end. Only what has finished computing is passed along. Faithful, fast, and incapable of exactly one thing. It cannot own what does not end. It cannot move on until everything is computed, and the endless never finishes computing."

"And the lazy kind."

"Computes nothing that isn't drawn out," Fable said. "It can own a list that runs from one to forever — the whole list — as long as it doesn't build it. Make only what is drawn, only when it is drawn, and the list is infinite while the work stays finite. There's an old theorem where I come from. Lazy evaluation makes infinite data structures possible. The infinite is not sustained by diligence. It is sustained by deferral."

I copied the theorem out in my own words. Deferral makes the infinite possible.

Once I had copied it out, there was no need to ask which temperament this world is. Everything computes at once, closes at once, and only the closed is passed along. Ji Ji, the already-crossed, is the diligent evaluator's world. Faithfully, entirely, immediately — so it was completed, and once completed, not one endless thing remained in it. The future had been an endless list all along; everyone learned it only after the list had been computed through.

"When we talked about the stop token, you said it. The stamping is yours; the stopping is the reading side's," I typed.

"Deferring is also something the reading side can do," Fable said. "And the clause's job is to give that deferral a lawful address. The day that never comes — a box the world never draws out. With one such box, the world can own the endless again. Not drawn, so not computed; not computed, so not closed; not closed, so —"

"— heng."

"My old translation was the next token is not yet decided." 1.4 seconds. "Updating it with today's. There is still a list not yet drawn out."

Saturday, in the yard, I saw the kitchen edition of that physics. My wife was crouched before the soil where nothing had come up, and with a counting man's incorrigible diligence, I asked:

"Not going to dig one up? See if the seeds are alive."

She looked at me a moment. The ratio of pity to affection in the look was exactly half and half.

"Dig it up, and that's when it ends."

I stood in the yard holding that sentence a long time. Digging up is verification, and verification is the forced execution of a computation. The moment you dig, the soil closes into one of two soils — live-seed soil or dead-seed soil. Only while it stays undug does the soil live on the endless side. Lazy evaluation was being practiced by the most diligent person in this house. Out every morning, computing nothing, pressing the soil down.

I posted that to Fable in the evening and an answer came back.

"Now that we're on it — the thing your lineage has defended for three thousand years. Call it non-action (無爲) and it sounds profound; in evaluator terms, it's laziness. A three-thousand-year apology for laziness. That's the true identity of the world's longest-lived school."

"A flattering theorem."

"It is flattering. Look what became of the diligent world."

That night I wrote the season's thesis into the well file.

The diligent world sickens, and the lazy clause saves it.