English
A refined form of the degree inequality for the norm in the coordinate ring; the degree is never 1 for any coordinate ring element, mirroring the prior result.
Русский
Уточненная форма неравенства степеней нормы в координатном кольце: степень никогда не равна 1.
LaTeX
$$$\\deg(\\operatorname{norm}_{R[X]}(x)) \\neq 1$$$
Lean4
/-- The addition of two nonsingular points on a Weierstrass curve in affine coordinates.
Given two nonsingular points `P` and `Q` in affine coordinates, use `P + Q` instead of `add P Q`. -/
def add [DecidableEq F] : W.Point → W.Point → W.Point
| 0, P => P
| P, 0 => P
| @some _ _ _ x₁ y₁ h₁, @some _ _ _ x₂ y₂ h₂ =>
if hxy : x₁ = x₂ ∧ y₁ = W.negY x₂ y₂ then 0 else some <| nonsingular_add h₁ h₂ hxy