OAI/AlgebraicGeometry/PlaneCurves/QuotientSections.lean
53 declarations, 0 contain sorry, 0 declared as axioms
Sections on the torus quotient and holomorphic chart equivalences; Holomorphic division producing quotient sections; Finite lists of quotient sections and their fibre values
- theorem
OAI.Nagata.W08.automorphicSection_analyticAtline 19Source documentation
Every concrete multiplier section is complex analytic at every genuine point.
theorem automorphicSection_analyticAt {τ γ : ℂ} {n : ℤ} (f : automorphicSections τ n γ) {z : ℂ} (hz : z ≠ 0) : AnalyticAt ℂ f.val z := by …Mentions: OAI.Nagata.W08.automorphicSections
- theorem
OAI.Nagata.W08.automorphicSection_analyticOnNhdline 27Source documentation
Analyticity on a neighborhood of each point of the punctured plane.
theorem automorphicSection_analyticOnNhd {τ γ : ℂ} {n : ℤ} (f : automorphicSections τ n γ) : AnalyticOnNhd ℂ f.val {z : ℂ | z ≠ 0} := …Mentions: OAI.Nagata.W08.automorphicSections
- def
OAI.Nagata.W08.EquivariantFunctionsline 46Source documentation
Scalar functions with the literal one-step multiplier law on the genuine cover.
def EquivariantFunctions (τ γ : Rˣ) (n : ℤ) := …
- def
OAI.Nagata.W08.QuotientSectionsline 50Source documentation
Actual right-inverse sections of the projection of the actual orbit quotient.
def QuotientSections (τ γ : Rˣ) (n : ℤ) := …
- theorem
OAI.Nagata.W08.multiplierIterate_graphline 55Source documentation
Equivariance under one generator propagates to every integer deck transformation.
theorem multiplierIterate_graph (τ γ : Rˣ) (n : ℤ) (f : EquivariantFunctions τ γ n) (k : ℤ) (z : Rˣ) : multiplierIterate τ γ n k (z, f.val z) = (τ ^ k * z, f.val (τ ^ k * z)) := by …Mentions: OAI.Nagata.W08.EquivariantFunctions
- def
OAI.Nagata.W08.quotientSectionOfEquivariantline 77Source documentation
An equivariant scalar function descends to an actual quotient section.
def quotientSectionOfEquivariant (τ γ : Rˣ) (n : ℤ) (f : EquivariantFunctions τ γ n) : QuotientSections τ γ n := …Mentions: OAI.Nagata.W08.EquivariantFunctions, OAI.Nagata.W08.QuotientSections
- theorem
OAI.Nagata.W08.quotientSectionOfEquivariant_applyline 91 - theorem
OAI.Nagata.W08.quotient_fibre_representativeline 97Source documentation
Every quotient fibre point has a scalar representative over each chosen lift of its base.
theorem quotient_fibre_representative (τ γ : Rˣ) (n : ℤ) (q : MultiplierQuotient τ γ n) (z : Rˣ) (hq : multiplierQuotientProjection τ γ n q = torusPointMk τ z) : ∃ t : R, (Quotient.mk _ (z, t) : MultiplierQuotient τ γ n) = q := by … - theorem
OAI.Nagata.W08.quotient_fibre_coordinate_injectiveline 113Source documentation
Freeness ensures that the scalar coordinate over a fixed lift is unique.
theorem quotient_fibre_coordinate_injective (τ γ : Rˣ) (n : ℤ) (hfree : ∀ k : ℤ, τ ^ k = 1 → k = 0) (z : Rˣ) : Function.Injective (fun t : R ↦ (Quotient.mk _ (z, t) : MultiplierQuotient τ γ n)) := by … - def
OAI.Nagata.W08.quotientSectionScalarline 126Source documentation
Extract the unique scalar over a chosen lift from an actual quotient section.
def quotientSectionScalar (τ γ : Rˣ) (n : ℤ) (s : QuotientSections τ γ n) (z : Rˣ) : R := …Mentions: OAI.Nagata.W08.QuotientSections
- theorem
OAI.Nagata.W08.quotientSectionScalar_representsline 131 - theorem
OAI.Nagata.W08.quotient_mk_multiplierStepline 139Source documentation
One generator identifies exactly the source multiplier-related representatives.
theorem quotient_mk_multiplierStep (τ γ : Rˣ) (n : ℤ) (z : Rˣ) (t : R) : (Quotient.mk _ (τ * z, (↑(γ * z ^ (-n)) : R) * t) : MultiplierQuotient τ γ n) = Quotient.mk _ (z, t) := by … - theorem
OAI.Nagata.W08.quotientSectionScalar_equivariantline 149Source documentation
The scalar extracted from an actual quotient section is genuinely equivariant.
theorem quotientSectionScalar_equivariant (τ γ : Rˣ) (n : ℤ) (hfree : ∀ k : ℤ, τ ^ k = 1 → k = 0) (s : QuotientSections τ γ n) (z : Rˣ) : quotientSectionScalar τ γ n s (τ * z) = (↑(γ * z ^ (-n)) : R) * quotientSectionScalar τ γ n s z := by …Mentions: OAI.Nagata.W08.QuotientSections, OAI.Nagata.W08.quotientSectionScalar
- def
OAI.Nagata.W08.equivariantOfQuotientSectionline 161Source documentation
Extract an equivariant function from an actual quotient section.
def equivariantOfQuotientSection (τ γ : Rˣ) (n : ℤ) (hfree : ∀ k : ℤ, τ ^ k = 1 → k = 0) (s : QuotientSections τ γ n) : EquivariantFunctions τ γ n := …Mentions: OAI.Nagata.W08.QuotientSections, OAI.Nagata.W08.EquivariantFunctions
- theorem
OAI.Nagata.W08.equivariantOfQuotientSection_left_inverseline 167Source documentation
Extracting after descending returns every original scalar value.
theorem equivariantOfQuotientSection_left_inverse (τ γ : Rˣ) (n : ℤ) (hfree : ∀ k : ℤ, τ ^ k = 1 → k = 0) (f : EquivariantFunctions τ γ n) : equivariantOfQuotientSection τ γ n hfree (quotientSectionOfEquivariant τ γ n f) = f := by …Mentions: OAI.Nagata.W08.EquivariantFunctions, OAI.Nagata.W08.equivariantOfQuotientSection, OAI.Nagata.W08.quotientSectionOfEquivariant
- theorem
OAI.Nagata.W08.quotientSectionOfEquivariant_right_inverseline 177Source documentation
Descending after extracting returns the actual original quotient section.
theorem quotientSectionOfEquivariant_right_inverse (τ γ : Rˣ) (n : ℤ) (hfree : ∀ k : ℤ, τ ^ k = 1 → k = 0) (s : QuotientSections τ γ n) : quotientSectionOfEquivariant τ γ n (equivariantOfQuotientSection τ γ n hfree s) = s := by …Mentions: OAI.Nagata.W08.QuotientSections, OAI.Nagata.W08.quotientSectionOfEquivariant, OAI.Nagata.W08.equivariantOfQuotientSection
- def
OAI.Nagata.W08.equivariantQuotientSectionEquivline 189Source documentation
The actual algebraic section/function equivalence of the actual quotient projection. Holomorphic compatibility is not asserted by this set-level equivalence.
def equivariantQuotientSectionEquiv (τ γ : Rˣ) (n : ℤ) (hfree : ∀ k : ℤ, τ ^ k = 1 → k = 0) : EquivariantFunctions τ γ n ≃ QuotientSections τ γ n where …Mentions: OAI.Nagata.W08.EquivariantFunctions, OAI.Nagata.W08.QuotientSections
- abbrev
OAI.Nagata.W06.TorusConfiguration.QuotientFibreline 211Source documentation
An actual fibre of the multiplier-orbit quotient projection.
abbrev QuotientFibre (τ γ : ℂˣ) (n : ℤ) (p : TorusPoint τ) := …
- def
OAI.Nagata.W06.TorusConfiguration.fibreRepresentativeline 215Source documentation
The vector with scalar c over the chosen nonzero lift z.
def fibreRepresentative (τ γ : ℂˣ) (n : ℤ) (z : ℂˣ) (c : ℂ) : QuotientFibre τ γ n (torusPointMk τ z) := … - theorem
OAI.Nagata.W06.TorusConfiguration.fibreRepresentative_injectiveline 219 - theorem
OAI.Nagata.W06.TorusConfiguration.fibreRepresentative_surjectiveline 225 - def
OAI.Nagata.W06.TorusConfiguration.fibreCoordinateEquivline 232Source documentation
A proved coordinate bijection for the actual quotient fibre over a fixed lift.
def fibreCoordinateEquiv (τ γ : ℂˣ) (n : ℤ) (hfree : ∀ k : ℤ, τ ^ k = 1 → k = 0) (z : ℂˣ) : ℂ ≃ QuotientFibre τ γ n (torusPointMk τ z) := … - theorem
OAI.Nagata.W06.TorusConfiguration.fibreCoordinateEquiv_applyline 238 - def
OAI.Nagata.W06.TorusConfiguration.fibreScaleAtLiftline 244Source documentation
Scalar multiplication between the actual two fibres in the specified covering frames. This finite-fibre map does not assert that these maps glue into a global bundle morphism.
def fibreScaleAtLift (τ γA γM : ℂˣ) (nA nM : ℤ) (hfree : ∀ k : ℤ, τ ^ k = 1 → k = 0) (z : ℂˣ) (P : ℂ) : QuotientFibre τ γA nA (torusPointMk τ z) → QuotientFibre τ γM nM (torusPointMk τ z) := … - theorem
OAI.Nagata.W06.TorusConfiguration.fibreScaleAtLift_representativeline 250 - theorem
OAI.Nagata.W06.TorusConfiguration.fibreScaleAtLift_oneline 261Source documentation
The source scalar-one vector is sent to the target scalar-P vector.
theorem fibreScaleAtLift_one (τ γA γM : ℂˣ) (nA nM : ℤ) (hfree : ∀ k : ℤ, τ ^ k = 1 → k = 0) (z : ℂˣ) (P : ℂ) : fibreScaleAtLift τ γA γM nA nM hfree z P (fibreRepresentative τ γA nA z 1) = fibreRepresentative τ γM nM z P := by …Mentions: OAI.Nagata.W06.TorusConfiguration.fibreScaleAtLift, OAI.Nagata.W06.TorusConfiguration.fibreRepresentative
- theorem
OAI.Nagata.W06.TorusConfiguration.fibreRepresentative_ne_zeroline 267 - def
OAI.Nagata.W08.automorphicToEquivariantline 291Source documentation
Restriction of the actual holomorphic section to its genuine unit-valued cover.
def automorphicToEquivariant (τ γ : ℂˣ) (n : ℤ) (f : automorphicSections (τ : ℂ) n (γ : ℂ)) : EquivariantFunctions τ γ n := …Mentions: OAI.Nagata.W08.automorphicSections, OAI.Nagata.W08.EquivariantFunctions
- theorem
OAI.Nagata.W08.automorphicToEquivariant_injectiveline 298Source documentation
Restriction loses no actual holomorphic sections.
theorem automorphicToEquivariant_injective (τ γ : ℂˣ) (n : ℤ) : Function.Injective (automorphicToEquivariant τ γ n) := by …Mentions: OAI.Nagata.W08.automorphicToEquivariant
- def
OAI.Nagata.W08.quotientSectionOfAutomorphicline 306Source documentation
An actual holomorphic multiplier function yields an actual right-inverse section.
def quotientSectionOfAutomorphic (τ γ : ℂˣ) (n : ℤ) (f : automorphicSections (τ : ℂ) n (γ : ℂ)) : QuotientSections τ γ n := …Mentions: OAI.Nagata.W08.automorphicSections, OAI.Nagata.W08.QuotientSections
- theorem
OAI.Nagata.W08.quotientSectionOfAutomorphic_applyline 311Source documentation
The quotient representative uses exactly the function's covering-frame scalar.
@[simp] theorem quotientSectionOfAutomorphic_apply (τ γ : ℂˣ) (n : ℤ) (f : automorphicSections (τ : ℂ) n (γ : ℂ)) (z : ℂˣ) : (quotientSectionOfAutomorphic τ γ n f).val (torusPointMk τ z) = (Quotient.mk _ (z, f.val (z : ℂ)) : MultiplierQuotient τ γ n) := rflMentions: OAI.Nagata.W08.automorphicSections, OAI.Nagata.W08.quotientSectionOfAutomorphic
- theorem
OAI.Nagata.W08.quotientSectionOfAutomorphic_scalarline 317Source documentation
Scalar extraction from the descended actual quotient section recovers the original value.
theorem quotientSectionOfAutomorphic_scalar (τ γ : ℂˣ) (n : ℤ) (hτ : ‖(τ : ℂ)‖ < 1) (f : automorphicSections (τ : ℂ) n (γ : ℂ)) (z : ℂˣ) : quotientSectionScalar τ γ n (quotientSectionOfAutomorphic τ γ n f) z = f.val (z : ℂ) := by …Mentions: OAI.Nagata.W08.automorphicSections, OAI.Nagata.W08.quotientSectionScalar, OAI.Nagata.W08.quotientSectionOfAutomorphic
- theorem
OAI.Nagata.W08.quotientSectionOfAutomorphic_injectiveline 324Source documentation
Distinct holomorphic covering functions give distinct actual quotient sections.
theorem quotientSectionOfAutomorphic_injective (τ γ : ℂˣ) (n : ℤ) (hτ : ‖(τ : ℂ)‖ < 1) : Function.Injective (quotientSectionOfAutomorphic τ γ n) := by … - theorem
OAI.Nagata.W08.quotientSection_fibreChartline 349Source documentation
The actual fibre chart recovers the unique scalar of an arbitrary quotient section.
theorem quotientSection_fibreChart (τ γ : ℂˣ) (n : ℤ) (hfree : ∀ k : ℤ, τ ^ k = 1 → k = 0) (U : Set ℂˣ) (hU : IsOpen U) (hinj : Set.InjOn (torusPointMk τ) U) (s : QuotientSections τ γ n) {z : ℂˣ} (hz : z ∈ U) : (multiplierFibreChart τ γ n hfree U hU hinj).symm (s.val (torusPointMk τ z)) = (z, quotientSectionScalar τ γ n s z) := by …Mentions: OAI.Nagata.W08.QuotientSections, OAI.Nagata.W08.quotientSectionScalar
- def
OAI.Nagata.W08.quotientChartScalarline 360Source documentation
The scalar local coordinate of a quotient section, expressed in the genuine complex base coordinate. Outside the chart domain its values have no geometric meaning.
def quotientChartScalar (τ γ : ℂˣ) (n : ℤ) (hfree : ∀ k : ℤ, τ ^ k = 1 → k = 0) (U : Set ℂˣ) (hU : IsOpen U) (hinj : Set.InjOn (torusPointMk τ) U) (s : QuotientSections τ γ n) (w : ℂ) : ℂ := …Mentions: OAI.Nagata.W08.QuotientSections
- theorem
OAI.Nagata.W08.quotientChartScalar_eqline 369Source documentation
Exact local-coordinate formula for every actual section.
theorem quotientChartScalar_eq (τ γ : ℂˣ) (n : ℤ) (hfree : ∀ k : ℤ, τ ^ k = 1 → k = 0) (U : Set ℂˣ) (hU : IsOpen U) (hinj : Set.InjOn (torusPointMk τ) U) (s : QuotientSections τ γ n) {z : ℂˣ} (hz : z ∈ U) : quotientChartScalar τ γ n hfree U hU hinj s (z : ℂ) = quotientSectionScalar τ γ n s z := by …Mentions: OAI.Nagata.W08.QuotientSections, OAI.Nagata.W08.quotientChartScalar, OAI.Nagata.W08.quotientSectionScalar
- theorem
OAI.Nagata.W08.quotientChartScalar_automorphic_eqline 380Source documentation
The actual quotient fibre-coordinate function equals the original holomorphic scalar.
theorem quotientChartScalar_automorphic_eq (τ γ : ℂˣ) (n : ℤ) (hτ : ‖(τ : ℂ)‖ < 1) (U : Set ℂˣ) (hU : IsOpen U) (hinj : Set.InjOn (torusPointMk τ) U) (f : automorphicSections (τ : ℂ) n (γ : ℂ)) {z : ℂˣ} (hz : z ∈ U) : quotientChartScalar τ γ n (unitPeriod_free τ hτ) U hU hinj (quotientSectionOfAutomorphic τ γ n f) (z : ℂ) = f.val (z : ℂ) := by …Mentions: OAI.Nagata.W08.automorphicSections, OAI.Nagata.W08.quotientChartScalar, OAI.Nagata.W08.unitPeriod_free, OAI.Nagata.W08.quotientSectionOfAutomorphic
- theorem
OAI.Nagata.W08.quotientChartScalar_automorphic_differentiableAtline 390Source documentation
The descended actual section is holomorphic in every actual fibre chart.
theorem quotientChartScalar_automorphic_differentiableAt (τ γ : ℂˣ) (n : ℤ) (hτ : ‖(τ : ℂ)‖ < 1) (U : Set ℂˣ) (hU : IsOpen U) (hinj : Set.InjOn (torusPointMk τ) U) (f : automorphicSections (τ : ℂ) n (γ : ℂ)) {z : ℂˣ} (hz : z ∈ U) : DifferentiableAt ℂ (quotientChartScalar τ γ n (unitPeriod_free τ hτ) U hU hinj (quotientSectionOfAutomorphic τ γ n f)) (z : ℂ) := by …Mentions: OAI.Nagata.W08.automorphicSections, OAI.Nagata.W08.quotientChartScalar, OAI.Nagata.W08.unitPeriod_free, OAI.Nagata.W08.quotientSectionOfAutomorphic
- theorem
OAI.Nagata.CoefficientSpaces.exists_holomorphic_quotientline 414Source documentation
Quotient construction directly from genuine holomorphic multiplier sections: analyticity is derived, with no additional analyticity hypotheses.
theorem exists_holomorphic_quotient {τ γ δ : ℂ} {n s : ℤ} (hτ : τ ≠ 0) (hδ : δ ≠ 0) (f : Nagata.W08.automorphicSections τ n γ) (P : Nagata.W08.automorphicSections τ s δ) (k : ℕ) (hzero : ∀ z ≠ 0, P.val z = 0 → deriv P.val z ≠ 0 ∧ (k : ℕ∞) ≤ analyticOrderAt f.val z) : ∃ G : Nagata.W08.automorphicSections τ (n - (k : ℤ) * s) (γ / δ ^ k), ∀ z ≠ 0, f.val z = P.val z ^ k * G.val z := …Mentions: OAI.Nagata.W08.automorphicSections
- theorem
OAI.Nagata.CoefficientSpaces.exists_low_holomorphic_coefficientline 427Source documentation
The actual low coefficient extension without redundant analytic assumptions.
theorem exists_low_holomorphic_coefficient {τ L Q : ℂ} (hτ : τ ≠ 0) (hL : L ≠ 0) (hQ : Q ≠ 0) (d m j : ℤ) (hj : j ≤ m) (P : Nagata.W08.automorphicSections τ 9 Q) (f : Nagata.W08.automorphicSections τ (3 * (d - 3 * j)) (L ^ (d - 3 * j))) (hzero : ∀ z ≠ 0, P.val z = 0 → deriv P.val z ≠ 0 ∧ ((m - j).toNat : ℕ∞) ≤ analyticOrderAt f.val z) : ∃ g ∈ coefficientSpace τ L Q d m j P.val, ∀ z ≠ 0, f.val z = P.val z ^ (m - j).toNat * g z := …Mentions: OAI.Nagata.W08.automorphicSections, OAI.Nagata.CoefficientSpaces.coefficientSpace
- def
OAI.Nagata.W08.IsChartHolomorphicline 459Source documentation
Standard local-coordinate holomorphy for an actual section of the quotient projection.
def IsChartHolomorphic (τ γ : ℂˣ) (n : ℤ) (hτ : ‖(τ : ℂ)‖ < 1) (s : QuotientSections τ γ n) : Prop := …Mentions: OAI.Nagata.W08.QuotientSections
- def
OAI.Nagata.W08.quotientSectionZeroScalarline 466Source documentation
The unique scalar extracted from an actual section, represented by a zero extension.
def quotientSectionZeroScalar (τ γ : ℂˣ) (n : ℤ) (s : QuotientSections τ γ n) (w : ℂ) : ℂ := …
Mentions: OAI.Nagata.W08.QuotientSections
- theorem
OAI.Nagata.W08.quotientSectionZeroScalar_zeroline 469 - theorem
OAI.Nagata.W08.quotientSectionZeroScalar_unitline 473 - theorem
OAI.Nagata.W08.quotientSectionZeroScalar_differentiableAtline 481Source documentation
Holomorphy in an actual fibre chart implies holomorphy of the extracted covering scalar.
theorem quotientSectionZeroScalar_differentiableAt (τ γ : ℂˣ) (n : ℤ) (hτ : ‖(τ : ℂ)‖ < 1) (s : QuotientSections τ γ n) (hs : IsChartHolomorphic τ γ n hτ s) {w : ℂ} (hw : w ≠ 0) : DifferentiableAt ℂ (quotientSectionZeroScalar τ γ n s) w := by …Mentions: OAI.Nagata.W08.QuotientSections, OAI.Nagata.W08.IsChartHolomorphic, OAI.Nagata.W08.quotientSectionZeroScalar
- theorem
OAI.Nagata.W08.quotientSectionZeroScalar_automorphyline 496Source documentation
The extracted scalar satisfies the actual multiplier equation.
theorem quotientSectionZeroScalar_automorphy (τ γ : ℂˣ) (n : ℤ) (hτ : ‖(τ : ℂ)‖ < 1) (s : QuotientSections τ γ n) {w : ℂ} (hw : w ≠ 0) : quotientSectionZeroScalar τ γ n s ((τ : ℂ) * w) = (γ : ℂ) * w ^ (-n) * quotientSectionZeroScalar τ γ n s w := by …Mentions: OAI.Nagata.W08.QuotientSections, OAI.Nagata.W08.quotientSectionZeroScalar
- def
OAI.Nagata.W08.automorphicOfChartHolomorphicline 507Source documentation
Extract a genuine holomorphic multiplier function from a chart-holomorphic actual section.
def automorphicOfChartHolomorphic (τ γ : ℂˣ) (n : ℤ) (hτ : ‖(τ : ℂ)‖ < 1) (s : QuotientSections τ γ n) (hs : IsChartHolomorphic τ γ n hτ s) : automorphicSections (τ : ℂ) n (γ : ℂ) := …Mentions: OAI.Nagata.W08.QuotientSections, OAI.Nagata.W08.IsChartHolomorphic, OAI.Nagata.W08.automorphicSections
- theorem
OAI.Nagata.W08.automorphicOfChartHolomorphic_right_inverseline 515Source documentation
Descent of the extracted holomorphic scalar recovers the actual original section.
theorem automorphicOfChartHolomorphic_right_inverse (τ γ : ℂˣ) (n : ℤ) (hτ : ‖(τ : ℂ)‖ < 1) (s : QuotientSections τ γ n) (hs : IsChartHolomorphic τ γ n hτ s) : quotientSectionOfAutomorphic τ γ n (automorphicOfChartHolomorphic τ γ n hτ s hs) = s := by …Mentions: OAI.Nagata.W08.QuotientSections, OAI.Nagata.W08.IsChartHolomorphic, OAI.Nagata.W08.quotientSectionOfAutomorphic, OAI.Nagata.W08.automorphicOfChartHolomorphic
- theorem
OAI.Nagata.W08.quotientSectionOfAutomorphic_isChartHolomorphicline 528Source documentation
When the actual chart slices cover the base, descent is holomorphic everywhere.
theorem quotientSectionOfAutomorphic_isChartHolomorphic (τ γ : ℂˣ) (n : ℤ) (hτ : ‖(τ : ℂ)‖ < 1) (hcover : ∀ z : ℂˣ, ∃ U : Set ℂˣ, ∃ _ : IsOpen U, ∃ _ : Set.InjOn (torusPointMk τ) U, z ∈ U) (f : automorphicSections (τ : ℂ) n (γ : ℂ)) : IsChartHolomorphic τ γ n hτ (quotientSectionOfAutomorphic τ γ n f) := by …Mentions: OAI.Nagata.W08.automorphicSections, OAI.Nagata.W08.IsChartHolomorphic, OAI.Nagata.W08.quotientSectionOfAutomorphic
- def
OAI.Nagata.W08.holomorphicQuotientSectionEquivline 538 - theorem
OAI.Nagata.W08.positivePeriod_norm_lt_oneline 572Source documentation
The source's actual unit-valued positive period has norm less than one.
theorem positivePeriod_norm_lt_one {τ : ℝ} (hτ : 0 < τ) (hτone : τ < 1) : ‖((positivePeriod τ hτ : ℂˣ) : ℂ)‖ < 1 := by … - theorem
OAI.Nagata.W08.sourcePeriod_chartCoverline 578Source documentation
Actual injective open slices cover every source covering-space point.
theorem sourcePeriod_chartCover {τ : ℝ} (hτ : 0 < τ) (hτone : τ < 1) : ∀ z : ℂˣ, ∃ U : Set ℂˣ, ∃ _ : IsOpen U, ∃ _ : Set.InjOn (torusPointMk (positivePeriod τ hτ)) U, z ∈ U := by … - def
OAI.Nagata.W08.sourceHolomorphicQuotientSectionEquivline 586