Module

LaurentPolynomial_isUnit_iff_exists_C_mul_T.lean

Nyll.AlgebraicCurves.Foundations.Polynomial.LaurentPolynomial_isUnit_iff_exists_C_mul_T
1 declaration indexed from sourceView source ↗

Laurent Polynomial is Unit iff exists C mul T

Imports2
  • Mathlib.Algebra.Polynomial.Laurent
  • Mathlib.Algebra.Polynomial.RingDivision
Imported by1

Declarations

LaurentPolynomial.isUnit_iff_exists_C_mul_T
Source context 4 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.Polynomial.Proofs.LaurentPolynomial_isUnit_iff_exists_C_mul_T
open LaurentPolynomial
universe u
theorem _root_.LaurentPolynomial.isUnit_iff_exists_C_mul_T
    {R : Type u} [CommRing R] [IsDomain R] (f : R[T;T⁻¹]) :
    IsUnit f ↔ ∃ (c : Rˣ) (n : ℤ), f = C (c : R) * T n