Numerical assembly of plane-curve Proposition 2 #
This module isolates the final numerical use of the powered-image relation. The geometric Wronskian estimate is supplied pointwise; the remaining degree, index, and trivial-gcd bookkeeping is discharged here in both coordinate orientations.
theorem
BGS.CorvajaZannier.planeCurvePropositionTwo_natural_of_auxiliaryBounds
{K : Type u_1}
[Field K]
[DecidableEq K]
[Finite K]
{f : MvPolynomial (Fin 2) K}
(hf : Irreducible f)
(hpartialFirst : (MvPolynomial.pderiv 0) f ≠ 0)
(hpartialSecond : (MvPolynomial.pderiv 1) f ≠ 0)
(m n p Chi : ℕ)
(hm : 0 < m)
(hn : 0 < n)
(hindex : Module.finrank (↥(PoweredImageOverFirst f m n)) (PlaneCurveFunctionField f) ≤ Chi)
(hauxiliary :
∀ (h k : ℕ),
0 < h →
0 < k →
PropositionTwoParametersAreAdmissible (n * MvPolynomial.degreeOf 0 f) (m * MvPolynomial.degreeOf 1 f) p h k →
¬((transposeBivariate (poweredCoordinateImageRelation hf hpartialSecond m hm n)).natDegree ≤ k ∧ (poweredCoordinateImageRelation hf hpartialSecond m hm n).natDegree ≤ h) →
have hx := ⋯;
↑(finiteExtensionGcdWeightedDegree K (PlaneCurveFunctionField f) (1 - planeCurveFunction f 0 ^ m)
(1 - planeCurveFunction f 1 ^ n)) ≤ ↑(h + 2 * k) / ↑(h * k + h + k) * ↑(n * MvPolynomial.degreeOf 0 f) + ↑k / ↑(h * k + h + k) * ↑(m * MvPolynomial.degreeOf 1 f) + (↑(h * k + h + k) - 1) / 2 * ↑Chi)
:
PropositionTwoNumericalAlternatives (n * MvPolynomial.degreeOf 0 f) (m * MvPolynomial.degreeOf 1 f) p Chi
↑(planeCurveExhaustiveTorsionGcdWeightedDegree hf hpartialSecond m n)
Proposition 2 in the orientation (u,v)=(x^m,y^n).
theorem
BGS.CorvajaZannier.planeCurvePropositionTwo_swapped_of_auxiliaryBounds
{K : Type u_1}
[Field K]
[DecidableEq K]
{f : MvPolynomial (Fin 2) K}
(hf : Irreducible f)
(hpartialFirst : (MvPolynomial.pderiv 0) f ≠ 0)
(hpartialSecond : (MvPolynomial.pderiv 1) f ≠ 0)
(m n p Chi : ℕ)
(hm : 0 < m)
(hn : 0 < n)
(hindex : Module.finrank (↥(PoweredImageOverFirst f m n)) (PlaneCurveFunctionField f) ≤ Chi)
(hauxiliary :
∀ (h k : ℕ),
0 < h →
0 < k →
PropositionTwoParametersAreAdmissible (m * MvPolynomial.degreeOf 1 f) (n * MvPolynomial.degreeOf 0 f) p h k →
¬((poweredCoordinateImageRelation hf hpartialSecond m hm n).natDegree ≤ k ∧ (transposeBivariate (poweredCoordinateImageRelation hf hpartialSecond m hm n)).natDegree ≤ h) →
have hx := ⋯;
↑(finiteExtensionGcdWeightedDegree K (PlaneCurveFunctionField f) (1 - planeCurveFunction f 1 ^ n)
(1 - planeCurveFunction f 0 ^ m)) ≤ ↑(h + 2 * k) / ↑(h * k + h + k) * ↑(m * MvPolynomial.degreeOf 1 f) + ↑k / ↑(h * k + h + k) * ↑(n * MvPolynomial.degreeOf 0 f) + (↑(h * k + h + k) - 1) / 2 * ↑Chi)
:
PropositionTwoNumericalAlternatives (m * MvPolynomial.degreeOf 1 f) (n * MvPolynomial.degreeOf 0 f) p Chi
↑(planeCurveExhaustiveTorsionGcdWeightedDegree hf hpartialSecond m n)
Proposition 2 in the swapped orientation (u,v)=(y^n,x^m).