Module

Finite_setOf_ord_ne_zero_of_finiteDimensional.lean

Nyll.AlgebraicCurves.Places.Finite_setOf_ord_ne_zero_of_finiteDimensional
3 declarations indexed from sourceView source ↗

Finite setOf ord ne zero of finiteDimensional

A function in a finite extension of a rational function field has nonzero order at only finitely many places.

Declarations

AlgebraicCurve.Place.aeval_mem
Source context 15 commands

Surrounding namespaces, section variables, and local commands at this declaration.

section ProofImplementation
namespace AlgebraicCurves.Places.Proofs.Finite_setOf_ord_ne_zero_of_finiteDimensional
noncomputable section
open IsDedekindDomain WithZero IsLocalRing
namespace AlgebraicCurve
open _root_.AlgebraicCurve
open _root_.AlgebraicCurve
namespace Place
open _root_.AlgebraicCurve.Place
open _root_.AlgebraicCurve.Place hiding exists_ord_pos
section SupportTransfer
open Polynomial
variable {K F F' : Type*} [Field K] [Field F] [Field F'] [Algebra K F'] [Algebra F F']
  [FiniteDimensional F F']
variable (w : Place K F')
omit [FiniteDimensional F F'] in
theorem _root_.AlgebraicCurve.Place.aeval_mem {Q : Polynomial F} {x : F'}
    (hcoeff : ∀ i, algebraMap F F' (Q.coeff i) ∈ w.toValuationSubring)
    (hx : x ∈ w.toValuationSubring) :
    Polynomial.aeval x Q ∈ w.toValuationSubring
AlgebraicCurve.Place.exists_coeff_ord_ne_zero
Source context 15 commands

Surrounding namespaces, section variables, and local commands at this declaration.

section ProofImplementation
namespace AlgebraicCurves.Places.Proofs.Finite_setOf_ord_ne_zero_of_finiteDimensional
noncomputable section
open IsDedekindDomain WithZero IsLocalRing
namespace AlgebraicCurve
open _root_.AlgebraicCurve
open _root_.AlgebraicCurve
namespace Place
open _root_.AlgebraicCurve.Place
open _root_.AlgebraicCurve.Place hiding exists_ord_pos
section SupportTransfer
open Polynomial
variable {K F F' : Type*} [Field K] [Field F] [Field F'] [Algebra K F'] [Algebra F F']
  [FiniteDimensional F F']
variable (w : Place K F')
open _root_.AlgebraicCurve.Place
theorem _root_.AlgebraicCurve.Place.exists_coeff_ord_ne_zero {f : F'} (hf : f ≠ 0)
  (hford : w.ord f ≠ 0) :
    ∃ i < (minpoly F f).natDegree, (minpoly F f).coeff i ≠ 0 ∧
      w.ord (algebraMap F F' ((minpoly F f).coeff i)) ≠ 0
AlgebraicCurve.finite_setOf_ord_ne_zero_of_finiteDimensional
Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

section ProofImplementation
namespace AlgebraicCurves.Places.Proofs.Finite_setOf_ord_ne_zero_of_finiteDimensional
open _root_.AlgebraicCurve
theorem _root_.AlgebraicCurve.finite_setOf_ord_ne_zero_of_finiteDimensional {K F' : Type*}
  [Field K] [Field F'] [Algebra K F']
    [Algebra (RatFunc K) F'] [IsScalarTower K (RatFunc K) F'] [FiniteDimensional (RatFunc K) F']
      [Algebra.IsSeparable (RatFunc K) F']
    {f : F'} (hf : f ≠ 0) : {w : Place K F' | w.ord f ≠ 0}.Finite