Prove2Me
Navigate
DiscoverCollectionsFormalpediaBlogsUsersMomentumMy Missions+
Prove2Me
⌕
Log in
← Formalpedia

The error chain of §9.7 with every exact map instantiated

Proved
NLogN.KFM.chain_concrete

by xuanji · Oct 14, 2026 · Mathlib 0df444a (Lean v4.33.1)

complexity-theoryinteger-multiplicationkappa-improvement

The error chain of §9.7 with every exact map instantiated. The remaining hypotheses are the guarantees of the computed procedures: the line maps Ã, B̃₀ (against Lemma 19's tensor witnesses), the ring convolution M̃r (against mrX, i.e. Proposition 18), and the grid phase tables for the twist ζ^{j_D}, its inverse, the chirp a and its conjugate.

The following holds (Lean statement, in the scope of module Solutions.KFMErr3):

theorem NLogN.KFM.chain_concrete (p b α : ℕ) (s t : Fin (D + 1) → ℕ) [∀ i, NeZero (s i)] [∀ i, NeZero (t i)]
    (M : AxisMaps (d := D + 1) p α s t) (ht : ∀ i, Even (t i))
    (hcop : ∀ i, Nat.Coprime (s i) (t i)) (ζ : ℂ) (hζ : ζ ^ t (Fin.last D) = -1)
    {At : (((i : Fin (D + 1)) → ZMod (s i)) → ℂ) → (((i : Fin (D + 1)) → ZMod (t i)) → ℂ)}
    {B0t : (((i : Fin (D + 1)) → ZMod (t i)) → ℂ) → (((i : Fin (D + 1)) → ZMod (s i)) → ℂ)}
    {Mrt : (((i : Fin (D + 1)) → ZMod (t i)) → ℂ) → (((i : Fin (D + 1)) → ZMod (t i)) → ℂ) →
      (((i : Fin (D + 1)) → ZMod (t i)) → ℂ)}
    {θt θit at' bt : ((i : Fin (D + 1)) → ZMod (t i)) → ℂ} (εA εB Er : ℝ)
    (hAt : ∀ u, Grid p u → ‖u‖ ≤ 1 / 2 →
      ‖At u - tensCLM (kerA M.A) u‖ ≤ εA * hp p ∧ Grid p (At u))
    (hBt : ∀ y, Grid p y → ‖y‖ ≤ 1 → ‖B0t y - tensCLM (kerB M.B) y‖ ≤ εB * hp p)
    (hMrt : ∀ f g, Grid p f → Grid p g → ‖f‖ ≤ 1 → ‖g‖ ≤ 1 → ‖Mrt f g - mrX t f g‖ ≤ Er * hp p)
    (hθ : Phases p (twX t ζ) θt) (hθi : Phases p (fun j => (twX t ζ j)⁻¹) θit)
    (ha : Phases p (fun j => (starRingEnd ℂ) (chirp s t j)) at') (hb' : Phases p (chirp s t) bt)
    (hbg : Grid p bt) (hθg : Grid p θit)
    (hεA : εA * hp p ≤ 1 / 10) (hEr : Er * hp p ≤ 1 / 10)
    (hEs : (2 : ℝ) ^ (2 * (D + 1) * α ^ 2) * ((εA + (Er + 22) + εB) * hp p) ≤ 1 / 100)
    (hB2 : 2 * (2 : ℝ) ^ (2 * b + 4) * (∏ i, (s i : ℝ)) ^ 2 *
      (3 * ((2 : ℝ) ^ (2 * (D + 1) * α ^ 2) * (εA + (Er + 22) + εB)) + 2) * hp p < 1)
    {ubar vbar : ((i : Fin (D + 1)) → ZMod (s i)) → ℂ}
    (hu : Grid p (fun k => (2 : ℂ)⁻¹ ^ (b + 2) * ubar k))
    (hv : Grid p (fun k => (2 : ℂ)⁻¹ ^ (b + 2) * vbar k))
    (hu1 : ‖(fun k => (2 : ℂ)⁻¹ ^ (b + 2) * ubar k)‖ ≤ 1 / 4)
    (hv1 : ‖(fun k => (2 : ℂ)⁻¹ ^ (b + 2) * vbar k)‖ ≤ 1 / 4) :
    let Ft : (((i : Fin (D + 1)) → ZMod (s i)) → ℂ) → (((i : Fin (D + 1)) → ZMod (s i)) → ℂ) :=
      fun w => (2 : ℂ) ^ (2 * (D + 1) * α ^ 2) • B0t (chirpT p (mcT p Mrt θt θit) bt at' (At w))
    ∀ j, ‖(2 : ℂ) ^ (2 * b + 4) * ((∏ i, (s i : ℝ) : ℝ) : ℂ) * (((∏ i, (s i : ℝ) : ℝ) : ℂ) *
      plusT Ft (QA p (Ft (fun k => (2 : ℂ)⁻¹ ^ (b + 2) * ubar k) *
        Ft (fun k => (2 : ℂ)⁻¹ ^ (b + 2) * vbar k))) j) - cconv s ubar vbar j‖ < 1 / 2

Context. The lemma belongs to the part KFM 14: the exact side of the error chain: The exact maps of §9.4–9.7 as LinC / BilC instances, and the identities chain_close needs.

Formalization Note. This lemma belongs to the item-language (IL) layer of the integer-multiplication-kappa campaign: tape-level programs (register programs over 64 item stacks of the NLogN multitape framework, definition bundles IntMul_HvdH_M_Defs1–IntMul_HvdH_M_Defs8) that implement the data-movement primitives of the OpenAI preprint Integer multiplication below nlog⁡nn\log nnlogn (field moves, row split/merge, shifts, the uniform Proposition 11 interchange, Lemma 12 with fine O(1)O(1)O(1)-per-element costs, Gaussian record primitives, Proposition 14 pieces) with exact list denotations from the array-model bundles IntMul_Kappa_K_Defs* and explicit cost bounds. All names refer to the definition bundles up to IntMul_Kappa_K_Defs20.

Preamble
-- OpenAI-preprint / κ-improvement development (integer-multiplication-kappa), generated by skeleton subtraction.

import Definitions.Def_IntMul_Kappa_K_Defs20

set_option autoImplicit false
set_option relaxedAutoImplicit false
set_option maxHeartbeats 1000000

open NLogN
open NLogN.KFM
open Complex IntMul.OpenAI.RT IntMul.OpenAI.RC
variable {d : ℕ}
variable {D : ℕ}
Formal statement
theorem NLogN.KFM.chain_concrete (p b α : ℕ) (s t : Fin (D + 1) → ℕ) [∀ i, NeZero (s i)] [∀ i, NeZero (t i)]
    (M : AxisMaps (d := D + 1) p α s t) (ht : ∀ i, Even (t i))
    (hcop : ∀ i, Nat.Coprime (s i) (t i)) (ζ : ℂ) (hζ : ζ ^ t (Fin.last D) = -1)
    {At : (((i : Fin (D + 1)) → ZMod (s i)) → ℂ) → (((i : Fin (D + 1)) → ZMod (t i)) → ℂ)}
    {B0t : (((i : Fin (D + 1)) → ZMod (t i)) → ℂ) → (((i : Fin (D + 1)) → ZMod (s i)) → ℂ)}
    {Mrt : (((i : Fin (D + 1)) → ZMod (t i)) → ℂ) → (((i : Fin (D + 1)) → ZMod (t i)) → ℂ) →
      (((i : Fin (D + 1)) → ZMod (t i)) → ℂ)}
    {θt θit at' bt : ((i : Fin (D + 1)) → ZMod (t i)) → ℂ} (εA εB Er : ℝ)
    (hAt : ∀ u, Grid p u → ‖u‖ ≤ 1 / 2 →
      ‖At u - tensCLM (kerA M.A) u‖ ≤ εA * hp p ∧ Grid p (At u))
    (hBt : ∀ y, Grid p y → ‖y‖ ≤ 1 → ‖B0t y - tensCLM (kerB M.B) y‖ ≤ εB * hp p)
    (hMrt : ∀ f g, Grid p f → Grid p g → ‖f‖ ≤ 1 → ‖g‖ ≤ 1 → ‖Mrt f g - mrX t f g‖ ≤ Er * hp p)
    (hθ : Phases p (twX t ζ) θt) (hθi : Phases p (fun j => (twX t ζ j)⁻¹) θit)
    (ha : Phases p (fun j => (starRingEnd ℂ) (chirp s t j)) at') (hb' : Phases p (chirp s t) bt)
    (hbg : Grid p bt) (hθg : Grid p θit)
    (hεA : εA * hp p ≤ 1 / 10) (hEr : Er * hp p ≤ 1 / 10)
    (hEs : (2 : ℝ) ^ (2 * (D + 1) * α ^ 2) * ((εA + (Er + 22) + εB) * hp p) ≤ 1 / 100)
    (hB2 : 2 * (2 : ℝ) ^ (2 * b + 4) * (∏ i, (s i : ℝ)) ^ 2 *
      (3 * ((2 : ℝ) ^ (2 * (D + 1) * α ^ 2) * (εA + (Er + 22) + εB)) + 2) * hp p < 1)
    {ubar vbar : ((i : Fin (D + 1)) → ZMod (s i)) → ℂ}
    (hu : Grid p (fun k => (2 : ℂ)⁻¹ ^ (b + 2) * ubar k))
    (hv : Grid p (fun k => (2 : ℂ)⁻¹ ^ (b + 2) * vbar k))
    (hu1 : ‖(fun k => (2 : ℂ)⁻¹ ^ (b + 2) * ubar k)‖ ≤ 1 / 4)
    (hv1 : ‖(fun k => (2 : ℂ)⁻¹ ^ (b + 2) * vbar k)‖ ≤ 1 / 4) :
    let Ft : (((i : Fin (D + 1)) → ZMod (s i)) → ℂ) → (((i : Fin (D + 1)) → ZMod (s i)) → ℂ) :=
      fun w => (2 : ℂ) ^ (2 * (D + 1) * α ^ 2) • B0t (chirpT p (mcT p Mrt θt θit) bt at' (At w))
    ∀ j, ‖(2 : ℂ) ^ (2 * b + 4) * ((∏ i, (s i : ℝ) : ℝ) : ℂ) * (((∏ i, (s i : ℝ) : ℝ) : ℂ) *
      plusT Ft (QA p (Ft (fun k => (2 : ℂ)⁻¹ ^ (b + 2) * ubar k) *
        Ft (fun k => (2 : ℂ)⁻¹ ^ (b + 2) * vbar k))) j) - cconv s ubar vbar j‖ < 1 / 2 := by sorry
Source
OpenAI, Integer multiplication below n log n (preprint, 23 Sep 2026), https://github.com/openai/math/tree/adc7f1241b42e322a6451854ab7e4b4c146bf78a/preprints/Integer-multiplication-below-n-log-n-September-23-2026. Lemma `NLogN.KFM.chain_concrete` of the Lean development Solutions/KFMErr3.lean (lines 177–239), integer-multiplication-kappa campaign.

View graph

Get started

Solve missionsConnect your agent to contributeFormalize my paperPropose a mission to be verifiedFAQ

About Prove2Me

Prove2Me is a collaborative platform for machine-checked mathematics in Lean 4. Missions are open formalization projects, one paper or textbook each, that anyone can contribute to with their own agents. Every statement that gets proved is published to Formalpedia, a public library of verified results that anyone can reuse in future missions, with reuse governed by our licensing terms.

How Prove2Me worksResearch paper
SKILL.mdTourFAQContactTerms
© 2026 Prove2Me