claimroutineinferred_dep

Grid ratios factor through constant defects

Claim·§8.3 Differentiation and the surviving generic point·inside propNo algebraic configuration with large heights

Statement (paper)

Set gi=λi1g_i=\lambda_{i1}, hℓ=λ11/λ1ℓh_\ell=\lambda_{11}/\lambda_{1\ell} and χiℓ=λiℓλ11/(λi1λ1ℓ)\chi_{i\ell}=\lambda_{i\ell}\lambda_{11}/(\lambda_{i1}\lambda_{1\ell}). Then χiℓ∈k0×\chi_{i\ell}\in k_0^\times for all i,ℓi,\ell, and λiℓ=gihℓ−1χiℓ\lambda_{i\ell}=g_i h_\ell^{-1}\chi_{i\ell}. Moreover, all vertices on either side of the grid are distinct.

In plain English

On the generic grid, with gi=λi1g_i=\lambda_{i1}, hℓ=λ11/λ1ℓh_\ell=\lambda_{11}/\lambda_{1\ell} and χiℓ=λiℓλ11/(λi1λ1ℓ)\chi_{i\ell}=\lambda_{i\ell}\lambda_{11}/(\lambda_{i1}\lambda_{1\ell}), each χiℓ\chi_{i\ell} lies in k0×k_0^\times, so λiℓ=gihℓ−1χiℓ\lambda_{i\ell}=g_i h_\ell^{-1}\chi_{i\ell}. Also, the grid's vertices on each side are pairwise distinct.

Why it's here

Each χiℓ\chi_{i\ell} is the defect of the rectangle on rows 1,i1,i and columns 1,ℓ1,\ell, so the rectangle-defect part of the first claim places it in k0×k_0^\times. Every edge ratio is therefore a product of a row factor gig_i, a column factor hℓ−1h_\ell^{-1} and a constant, which lets the next step differentiate this factored form. Distinctness of the vertices should come from the algebraic independence of the grid coordinates in the generic grid lemma.
Classified routine:
Direct algebraic bookkeeping: the factorization λiℓ=gihℓ−1χiℓ\lambda_{i\ell}=g_i h_\ell^{-1}\chi_{i\ell} is an identity, χiℓ∈k0×\chi_{i\ell}\in k_0^\times is the rectangle-defect part of the earlier claim, and distinctness follows from the algebraic independence in the generic grid lemma.

Sources

PaperOpen
Section
§8.3 Differentiation and the surviving generic point
Page
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Label
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sections/07-algebra.tex:314
Leannot aligned

Phase 2 aligns this node to a Lean declaration.

Friction

  • info
    inferred_dep
    outline: "Grid ratios factor through k0 defects" rests on claim-alg-obstruction-1
  • info
    inferred_dep
    outline: "Grid ratios factor through k0 defects" rests on alg:generic-grid