The arbitrary-atlas transported formulation of smooth Poincaré
DefinitionSP4PullbackFormThis defines the predicate asserting that, for every compact Hausdorff Type-0 smooth four-manifold N with an arbitrary given atlas and every homeomorphism e from N to the standard sphere, there exists a smooth-groupoid structomorphism from the given atlas to the atlas pulled back along e. Its underlying self-homeomorphism of N need not be the identity. The definition does not prove the predicate.
-- Derived from frozen local sources; exact source/hash provenance in items.json.
import Definitions.Def_SP4Sphere
import Definitions.Def_SP4PullbackCharts
set_option autoImplicit false
namespace SP4Mission
open scoped Manifold ContDiff
noncomputable section
section Transport
variable {N : Type} [TopologicalSpace N]
def SPC4Pullback : Prop :=
∀ (N : Type) [TopologicalSpace N] [T2Space N] [CompactSpace N]
[cs : ChartedSpace (EuclideanSpace ℝ (Fin 4)) N] [IsManifold (𝓡 4) ∞ N],
∀ e : N ≃ₜ S4,
Nonempty (@Structomorph (EuclideanSpace ℝ (Fin 4)) _
(contDiffGroupoid ∞ (𝓡 4)) N N _ _ cs e.sp4MissionPullbackChartedSpace)
end Transport
section Bridge
open Set ChartedSpace
variable {𝕜 : Type*} [NontriviallyNormedField 𝕜] {E : Type*} [NormedAddCommGroup E]
[NormedSpace 𝕜 E] {H' : Type*} [TopologicalSpace H'] {I : ModelWithCorners 𝕜 E H'}
{X : Type*} [TopologicalSpace X] [ChartedSpace H' X]
{X' : Type*} [TopologicalSpace X'] [ChartedSpace H' X']
{m : ℕ∞ω} [IsManifold I m X] [IsManifold I m X']
end Bridge
end
end SP4Mission
Read-back
What the Lean code literally says, in plain math · Codex; the exact underlying model identifier is not exposed in this session.
Let , with its subspace topology and standard stereographic smooth structure modeled on . The proposition states that, for every type in the base universe equipped with a topology making it compact and Hausdorff, every specified charted-space structure on modeled on with -compatible transitions, and every homeomorphism , there exists a homeomorphism preserving the smooth structure from on the source to the structure pulled back from along on the target. The pulled-back atlas consists exactly of for sphere atlas charts , with source , target , inverse , and preferred chart at induced by the sphere's preferred chart at . Structure preservation means that for every chart in and every sphere atlas chart , the open partial homeomorphism represented by belongs to the groupoid of smooth local transformations of : both it and its inverse are on their domains. The choice of may depend on , and no condition that be the identity or unique is present. The quantifier over has no instances if is empty.
Confirmed by the mission captain (proposal self-audit).