Transport of the constructed good hyperplane to coordinates suited to the universal Noether family.
theorem
CCDN.graphHyperplaneRestriction_rename
{K : Type u_1}
{σ : Type u_2}
{τ : Type u_3}
[CommRing K]
[Fintype σ]
[Fintype τ]
(e : σ ≃ τ)
(a : τ → K)
(f : MvPolynomial (Option σ) K)
:
(MvPolynomial.rename ⇑e) ((graphHyperplaneRestriction (a ∘ ⇑e)) f) = (graphHyperplaneRestriction a) ((MvPolynomial.rename ⇑e.optionCongr) f)
Restriction to the graph hyperplane x_none = ∑ a j * x j commutes with renaming the
coordinates along an equivalence e.
theorem
CCDN.exists_geometrically_good_graph_reindexed
{n : ℕ}
(f : MvPolynomial (Option (Option (Fin (2 + n)))) ℤ)
(hir : AbsolutelyIrreducible f)
(hd : 0 < f.totalDegree)
:
∃ (a : Option (Fin (2 + n)) → ℚ),
AbsolutelyIrreducibleRat ((graphHyperplaneRestriction a) ((MvPolynomial.map (Int.castRingHom ℚ)) f))
The constructed bounded integer normal yields a geometrically integral rational graph section in the double-Option coordinates.