Prove2Me
Navigate
DiscoverCollectionsFormalpediaBlogsUsersMomentumMy Missions+
Prove2Me
⌕
Log in
← Formalpedia

The B̃₀ axis step

Proved
NLogN.AX.bap0AxP_all

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

complexity-theoryinteger-multiplicationkappa-improvement

The B̃₀ axis step.

The following holds (Lean statement, in the scope of module Solutions.KFMBap0Ax):

theorem NLogN.AX.bap0AxP_all (M : MulSpec) (p s t α m kb Bi Bo mm Φ Bacc Q Bq : ℕ) (rest : List ℕ)
    (hM : MulBnd M mm Φ) (H : BapHyp p s t α kb Bi Bo mm Bacc Q) (HT : TabHypB p s t α Bq)
    (hα : 1 ≤ α) (HQ : AxQ t s m kb Bi Bo Q) (hmr : m = rest.prod)
    (st : IState HS) (L : List (ℤ × ℤ)) (Rest : List Item) (hR : BapRegs p s t α m kb st)
    (hD : st.G NLogN.GL.gD = gints L ++ Rest) (hL : L.length = t * m) (hLB : NLogN.GL.GB Bi L) :
    bap0AxP.run st = st.upd NLogN.GL.gD (gints (tensorGo [(s, b0L p s t α)] (t :: rest) L) ++ Rest) ∧
      bap0AxP.ok M st ∧ bap0AxP.cost M st ≤ bap0AxCost p s t α m kb Bi mm Φ Bacc Q Bq ∧
      (tensorGo [(s, b0L p s t α)] (t :: rest) L).length = m * s ∧
      NLogN.GL.GB Bo (tensorGo [(s, b0L p s t α)] (t :: rest) L)

Context. The lemma belongs to the part Item 12 (machine side, part 2): the B̃₀ axis program bap0AxP: nlogn's bapAxP (HAx8) with the slice program bapSlP replaced by the permutation-free bap0SlP (KFMBap0). The table building is unchanged; the two key tables (ptKR, psKR) are still built and removed but no longer read. That costs O((t+s)·Bq²) per axis call. On gD = gints L ++ R (L of dims t :: rest) it computes gints (tensorGo [(s, b0L p s t α)] (t :: rest) L) ++ R. The proof is nlogn's bapAxP_all with the slice lemmas renamed. The declarations live in NLogN.AX (as in HAx8) so that names resolve exactly as there.

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_Defs18.

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

import Definitions.Def_IntMul_Kappa_K_Defs18

set_option autoImplicit false
set_option relaxedAutoImplicit false
set_option maxHeartbeats 1000000

set_option linter.unusedSimpArgs false
open NLogN
open NLogN.AX
open IntMul NLogN IntMul.HvdH.Ref NLogN.GL NLogN.Rsp NLogN.KFM
set_option maxHeartbeats 16000000
Formal statement
theorem NLogN.AX.bap0AxP_all (M : MulSpec) (p s t α m kb Bi Bo mm Φ Bacc Q Bq : ℕ) (rest : List ℕ)
    (hM : MulBnd M mm Φ) (H : BapHyp p s t α kb Bi Bo mm Bacc Q) (HT : TabHypB p s t α Bq)
    (hα : 1 ≤ α) (HQ : AxQ t s m kb Bi Bo Q) (hmr : m = rest.prod)
    (st : IState HS) (L : List (ℤ × ℤ)) (Rest : List Item) (hR : BapRegs p s t α m kb st)
    (hD : st.G NLogN.GL.gD = gints L ++ Rest) (hL : L.length = t * m) (hLB : NLogN.GL.GB Bi L) :
    bap0AxP.run st = st.upd NLogN.GL.gD (gints (tensorGo [(s, b0L p s t α)] (t :: rest) L) ++ Rest) ∧
      bap0AxP.ok M st ∧ bap0AxP.cost M st ≤ bap0AxCost p s t α m kb Bi mm Φ Bacc Q Bq ∧
      (tensorGo [(s, b0L p s t α)] (t :: rest) L).length = m * s ∧
      NLogN.GL.GB Bo (tensorGo [(s, b0L p s t α)] (t :: rest) L) := 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.AX.bap0AxP_all` of the Lean development Solutions/KFMBap0Ax.lean (lines 80–383), 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