Module

Place_ord_eq_zero_of_evalAt_ne_zero.lean

Nyll.AlgebraicCurves.Places.Place_ord_eq_zero_of_evalAt_ne_zero
1 declaration indexed from sourceView source ↗

A nonzero place evaluation has order zero

Declarations

AlgebraicCurve.Place.ord_eq_zero_of_evalAt_ne_zero

Nonzero evaluation at a rational place detects an actual unit in its valuation ring, and hence a function of order zero.

Source context 2 commands

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

noncomputable section
namespace AlgebraicCurve.Place
theorem ord_eq_zero_of_evalAt_ne_zero
    {K F : Type*} [Field K] [Field F] [Algebra K F]
    (v : Place K F) (hv : v.IsRational) {f : F}
    (h : v.evalAt f ≠ 0) : v.ord f = 0