OAI/AlgebraicGeometry/StableCoordinate/SourceCoordinateTransport.lean
2 declarations, 0 contain sorry, 0 declared as axioms
Literal-polynomial coordinate systems in the canonical source algebra
The source presentation carries exactly aX 0 to the prescribed polynomial
f. This reverses the presentation equivalence so a hypothetical coordinate
automorphism of the literal four-variable polynomial gives precisely the
coordinate-system direction used by the leading-derivation construction.
No ambient automorphism is restricted or excluded.
- theorem
OAI.StableCoordinate.Obstruction.f_coordinate_iff_source_coordinate_systemline 22Source documentation
The exact coordinate predicate is equivalent to a polynomial coordinate system on the canonical source algebra, with its first coordinate equal to
p. The equivalence quantifies over all ambient polynomial automorphisms.theorem f_coordinate_iff_source_coordinate_system : IsCoordinate (by decide : 0 < 4) StableCoordinate.f ↔ ∃ e : StableCoordinate.R 4 ≃ₐ[ℂ] A ℂ, e (X 0) = aX ℂ 0 := by …Mentions: OAI.StableCoordinate.IsCoordinate, OAI.StableCoordinate.f, OAI.StableCoordinate.R, OAI.StableCoordinate.Obstruction.A, OAI.StableCoordinate.Obstruction.aX
- theorem
OAI.StableCoordinate.Obstruction.source_coordinate_system_of_f_coordinateline 34Source documentation
A four-variable coordinate for the literal polynomial supplies the actual source-coordinate equivalence needed by the negative proof.
theorem source_coordinate_system_of_f_coordinate (h : IsCoordinate (by decide : 0 < 4) StableCoordinate.f) : ∃ e : StableCoordinate.R 4 ≃ₐ[ℂ] A ℂ, e (X 0) = aX ℂ 0 := …Mentions: OAI.StableCoordinate.IsCoordinate, OAI.StableCoordinate.f, OAI.StableCoordinate.R, OAI.StableCoordinate.Obstruction.A, OAI.StableCoordinate.Obstruction.aX