For pairwise coprime monic `g i` over a field, `∑ h i ∏_{j ≠ i} g j = 0` with `deg h i < deg g i` forces all `h i = 0`.
ProvedTypeDensity.coprime_family_linear_injectivetype-density
For pairwise coprime monic g i over a field, ∑ h i ∏_{j ≠ i} g j = 0 with deg h i < deg g i forces all h i = 0.
Preamble
import Definitions.Def_TypeDensity_Basic import Definitions.Def_TypeDensity_Measure_AdicCylinders import Definitions.Def_TypeDensity_Measure_HenselProducts import Definitions.Def_TypeDensity_Unramified_Extension import Mathlib.FieldTheory.RatFunc.Basic import Mathlib.MeasureTheory.Measure.Haar.Unique import Mathlib.NumberTheory.ArithmeticFunction.Moebius import Mathlib.NumberTheory.Padics.PadicIntegers import Mathlib.RingTheory.IntegralClosure.IntegralRestrict import Mathlib.RingTheory.MvPowerSeries.Basic import Mathlib.RingTheory.RamificationInertia.Basic import Mathlib.Topology.Algebra.Nonarchimedean.AdicTopology import Mathlib.Topology.Algebra.MvPolynomial import Mathlib.Algebra.Group.Pi.Units import Mathlib.Order.CompletePartialOrder import Mathlib.RingTheory.Henselian import Mathlib.RingTheory.Polynomial.Resultant.Basic import Mathlib.RingTheory.RegularLocalRing.Defs import Mathlib.RingTheory.SimpleRing.Principal set_option autoImplicit false open TypeDensity open Polynomial IsLocalRing MeasureTheory open scoped Classical
Formal statement
theorem TypeDensity.coprime_family_linear_injective (k ι : Type) [Field k] [Fintype ι] (g : ι → Polynomial k)
(hg : ∀ i, (g i).Monic) (hc : ∀ i j, i ≠ j → IsCoprime (g i) (g j)) (h : ι → Polynomial k)
(hdeg : ∀ i, (h i).degree < ((g i).natDegree : WithBot ℕ))
(hsum : ∑ i, h i * ∏ j ∈ Finset.univ.erase i, g j = 0) :
∀ i, h i = 0 := by sorrySource
TypeDensity/Unramified/Extension.lean#L407-L435