OAI/AlgebraicGeometry/StableCoordinate/AllFibers.lean

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3 declarations, 0 contain sorry, 0 declared as axioms

Every complex fiber of the exact polynomial

The two explicit quotient-algebra calculations cover every parameter, including zero. Together with the noncoordinate theorem, these equivalences show that every fiber is affine three-space and its embedding is nonrectifiable.

  1. theorem OAI.StableCoordinate.all_fibers_isAffineThreeSpace line 19

    Source documentation

    Every complex fiber of the specified polynomial has the coordinate algebra of affine three-space, with no exceptional parameters.

    theorem all_fibers_isAffineThreeSpace :
        ∀ t : ℂ, IsAffineThreeSpaceFiber t := by
    …

    Mentions: OAI.StableCoordinate.IsAffineThreeSpaceFiber

  2. def OAI.StableCoordinate.exactFiberEquiv line 28

    Source documentation

    An actual complex algebra equivalence for each fiber.

    noncomputable def exactFiberEquiv (t : ℂ) : FiberRing t ≃ₐ[ℂ] R 3 :=
    …

    Mentions: OAI.StableCoordinate.FiberRing, OAI.StableCoordinate.R

  3. theorem OAI.StableCoordinate.fiberPackage_of_noncoordinate line 33

    Source documentation

    With the unrestricted four-variable coordinate obstruction, the already proved all-fiber calculation supplies the entire geometric principal group.

    theorem fiberPackage_of_noncoordinate
        (h : ¬ IsCoordinate (by decide : 0 < 4) f) : FiberPackage :=
    …

    Mentions: OAI.StableCoordinate.IsCoordinate, OAI.StableCoordinate.f, OAI.StableCoordinate.FiberPackage