OAI/CategoryTheory/Thomason/Simplicial/ExhaustionWeakEquivalence.lean
52 declarations, 0 contain sorry, 0 declared as axioms
Every realization point has unique nondegenerate interior coordinates
- theorem
OAI.Thomason.Construction.RealizationPrism.normalizeSimplex_fullSupportline 22 - theorem
OAI.Thomason.Construction.RealizationPrism.normalizeSupported_fullSupportline 30 - theorem
OAI.Thomason.Construction.RealizationPrism.normalization_fullSupportline 37Source documentation
No coordinate of the intrinsic nondegenerate representative vanishes.
theorem normalization_fullSupport (K : SSet.{0}) (x : SSet.toTop.obj K) : (normalization K x).2 ∈ fullSupport (normalization K x).1.dim := by …Mentions: OAI.Thomason.Construction.RealizationPrism.normalization, OAI.Thomason.Construction.RealizationPrism.fullSupport
- def
OAI.Thomason.Construction.RealizationPrism.interiorCoordinatesEquivline 45Source documentation
The underlying set of a realization is the disjoint union of nondegenerate simplex interiors. This does not give the disjoint-union topology.
def interiorCoordinatesEquiv (K : SSet.{0}) : SSet.toTop.obj K ≃ Σ s : K.N, fullSupport s.dim where …Mentions: OAI.Thomason.Construction.RealizationPrism.fullSupport
- theorem
OAI.Thomason.Construction.RealizationPrism.standard_boundary_carrier_iffline 80Source documentation
A supported simplex of the standard simplex belongs to its boundary precisely when some original barycentric coordinate vanishes.
theorem standard_boundary_carrier_iff (n : ℕ) (x : StdSimplex ℝ (Fin (n+1))) : simplexCarrier (Δ[n] : SSet.{0}) (SSet.yonedaEquiv (𝟙 _)) x ≤ SSet.boundary n ↔ ∃ i, x.weights i = 0 := by …Mentions: OAI.Thomason.Construction.RealizationPrism.simplexCarrier
- theorem
OAI.Thomason.Construction.RealizationPrism.standard_boundary_point_iffline 105Source documentation
The actual realized boundary has exactly the familiar zero-coordinate locus.
theorem standard_boundary_point_iff (n : ℕ) (x : StdSimplex ℝ (Fin (n+1))) : simplexPoint (Δ[n] : SSet.{0}) (SSet.yonedaEquiv (𝟙 _)) x ∈ Set.range (SSet.toTop.map (SSet.boundary n).ι).hom ↔ ∃ i, x.weights i = 0 := by …Mentions: OAI.Thomason.Construction.RealizationPrism.simplexPoint
- theorem
OAI.Thomason.Construction.RealizationPrism.simplexPoint_standard_idline 130Source documentation
The parameter map of the identity simplex is the inverse of the standard realization homeomorphism.
theorem simplexPoint_standard_id (n : ℕ) (x : StdSimplex ℝ (Fin (n+1))) : simplexPoint (Δ[n] : SSet.{0}) (SSet.yonedaEquiv (𝟙 _)) x = (SimplexCategory.mk n).toTopHomeo.symm x := by …Mentions: OAI.Thomason.Construction.RealizationPrism.simplexPoint
- def
OAI.Thomason.Construction.RealizationPrism.boundaryLocusline 143Source documentation
The boundary locus, including the empty boundary in dimension zero.
def boundaryLocus (n : ℕ) : Set (StdSimplex ℝ (Fin (n+1))) := …
- def
OAI.Thomason.Construction.RealizationPrism.boundaryCoordinatesline 147Source documentation
The barycentric coordinates of the actual boundary inclusion.
def boundaryCoordinates (n : ℕ) : C(SSet.toTop.obj (SSet.boundary n : SSet.{0}), StdSimplex ℝ (Fin (n+1))) := … - theorem
OAI.Thomason.Construction.RealizationPrism.boundaryCoordinates_isClosedEmbeddingline 152 - theorem
OAI.Thomason.Construction.RealizationPrism.range_boundaryCoordinatesline 157 - def
OAI.Thomason.Construction.RealizationPrism.boundaryHomeomorphline 177Source documentation
The actual boundary realization is homeomorphic to the zero-coordinate locus of the barycentric simplex.
def boundaryHomeomorph (n : ℕ) : SSet.toTop.obj (SSet.boundary n : SSet.{0}) ≃ₜ boundaryLocus n := …Mentions: OAI.Thomason.Construction.RealizationPrism.boundaryLocus
- theorem
OAI.Thomason.Construction.RealizationPrism.boundaryHomeomorph_inclusionline 184Source documentation
The homeomorphism identifies the realized boundary arrow with the actual barycentric subspace inclusion, not just with an abstract homeomorphic pair.
theorem boundaryHomeomorph_inclusion (n : ℕ) (x : SSet.toTop.obj (SSet.boundary n : SSet.{0})) : (boundaryHomeomorph n x).val = (SimplexCategory.mk n).toTopHomeo ((SSet.toTop.map (SSet.boundary n).ι).hom x) := rfl …Mentions: OAI.Thomason.Construction.RealizationPrism.boundaryHomeomorph
- def
OAI.Thomason.Construction.RealizationPrism.boundaryInclusionline 213Source documentation
The literal inclusion of the barycentric boundary subspace.
def boundaryInclusion (n : ℕ) : TopCat.of (boundaryLocus n) ⟶ TopCat.of (StdSimplex ℝ (Fin (n+1))) := …Mentions: OAI.Thomason.Construction.RealizationPrism.boundaryLocus
- def
OAI.Thomason.Construction.RealizationPrism.boundaryArrowIsoline 218Source documentation
The whole realized boundary arrow agrees with the barycentric pair.
def boundaryArrowIso (n : ℕ) : Arrow.mk (SSet.toTop.map (SSet.boundary n).ι) ≅ Arrow.mk (boundaryInclusion n) := …Mentions: OAI.Thomason.Construction.RealizationPrism.boundaryInclusion
- theorem
OAI.Thomason.Construction.RealizationPrism.singular_boundary_lifting_iffline 229Source documentation
Singular boundary filling is exactly lifting against the actual barycentric boundary inclusion.
theorem singular_boundary_lifting_iff {X Y : TopCat.{0}} (p : X ⟶ Y) (n : ℕ) : HasLiftingProperty (SSet.boundary n).ι (TopCat.toSSet.map p) ↔ HasLiftingProperty (boundaryInclusion n) p := …Mentions: OAI.Thomason.Construction.RealizationPrism.boundaryInclusion
- theorem
OAI.Thomason.Construction.RealizationPrism.singular_boundary_rlp_iffline 237Source documentation
The entire simplicial boundary lifting class has this concrete topological interpretation.
theorem singular_boundary_rlp_iff {X Y : TopCat.{0}} (p : X ⟶ Y) : I.rlp (TopCat.toSSet.map p) ↔ ∀ n, HasLiftingProperty (boundaryInclusion n) p := by …Mentions: OAI.Thomason.Construction.RealizationPrism.boundaryInclusion
- theorem
OAI.Thomason.Construction.RealizationPrism.singular_weak_of_boundary_liftingline 248Source documentation
Maps lifting against every barycentric boundary induce actual weak homotopy equivalences of singular realizations.
theorem singular_weak_of_boundary_lifting {X Y : TopCat.{0}} (p : X ⟶ Y) (h : ∀ n, HasLiftingProperty (boundaryInclusion n) p) : realizationWeakEquivalences (TopCat.toSSet.map p) := …Mentions: OAI.Thomason.Construction.RealizationPrism.boundaryInclusion, OAI.Thomason.Construction.realizationWeakEquivalences
- theorem
OAI.Thomason.Construction.RealizationPrism.realization_mono_liftingline 256Source documentation
Elementary barycentric boundary lifts extend over every realized simplicial monomorphism. This is the actual topological lifting property, obtained through the adjunction and the proved boundary generation theorem.
theorem realization_mono_lifting {X Y : TopCat.{0}} (p : X ⟶ Y) (h : ∀ n, HasLiftingProperty (boundaryInclusion n) p) {K L : SSet.{0}} (i : K ⟶ L) [Mono i] : HasLiftingProperty (SSet.toTop.map i) p := by …Mentions: OAI.Thomason.Construction.RealizationPrism.boundaryInclusion
- def
OAI.Thomason.Construction.RealizationPrism.relativeBoundaryExtensionline 267Source documentation
A concrete continuous extension preserving the prescribed map on a subcomplex and its image under
p.def relativeBoundaryExtension {X Y : TopCat.{0}} (p : X ⟶ Y) (h : ∀ n, HasLiftingProperty (boundaryInclusion n) p) (K : SSet.{0}) (A : K.Subcomplex) (a : SSet.toTop.obj (A : SSet) ⟶ X) (b : SSet.toTop.obj K ⟶ Y) (sq : CommSq a (SSet.toTop.map A.ι) p b) : SSet.toTop.obj K ⟶ X := by …Mentions: OAI.Thomason.Construction.RealizationPrism.boundaryInclusion
- theorem
OAI.Thomason.Construction.RealizationPrism.relativeBoundaryExtension_restrictline 276 - theorem
OAI.Thomason.Construction.RealizationPrism.relativeBoundaryExtension_compline 286 - theorem
OAI.Thomason.Construction.RealizationPrism.simplexPoint_as_realized_mapline 312 - theorem
OAI.Thomason.Construction.RealizationPrism.boundaryLocus_eq_compl_fullSupportline 321 - def
OAI.Thomason.Construction.RealizationPrism.cellBoundaryMapline 329Source documentation
The actual attaching map is the realization of the simplicial boundary followed by the given characteristic simplex.
def cellBoundaryMap (K : SSet.{0}) {n : ℕ} (s : K.obj (.op (.mk n))) : SSet.toTop.obj (SSet.boundary n : SSet.{0}) ⟶ SSet.toTop.obj K := … - theorem
OAI.Thomason.Construction.RealizationPrism.cellBoundaryMap_coordinatesline 333 - theorem
OAI.Thomason.Construction.RealizationPrism.range_cellBoundaryMapline 346 - theorem
OAI.Thomason.Construction.RealizationPrism.cell_boundary_eq_closure_diffline 355Source documentation
The boundary image is exactly the part of the closed characteristic cell outside its own interior, allowing arbitrary identifications of faces.
theorem cell_boundary_eq_closure_diff (K : SSet.{0}) (s : K.N) : Set.range (cellBoundaryMap K s.simplex).hom = closure (simplexPoint K s.simplex '' fullSupport s.dim) \ (simplexPoint K s.simplex '' fullSupport s.dim) := by …Mentions: OAI.Thomason.Construction.RealizationPrism.cellBoundaryMap, OAI.Thomason.Construction.RealizationPrism.simplexPoint, OAI.Thomason.Construction.RealizationPrism.fullSupport
- theorem
OAI.Thomason.Construction.RealizationPrism.carrier_interiorline 392Source documentation
An interior point has the whole characteristic simplex as its carrier.
theorem carrier_interior (K : SSet.{0}) {n : ℕ} (s : K.obj (.op (.mk n))) (x : StdSimplex ℝ (Fin (n+1))) (hx : x ∈ fullSupport n) : carrier K (simplexPoint K s x) = SSet.Subcomplex.ofSimplex s := by …Mentions: OAI.Thomason.Construction.RealizationPrism.fullSupport, OAI.Thomason.Construction.RealizationPrism.carrier, OAI.Thomason.Construction.RealizationPrism.simplexPoint
- theorem
OAI.Thomason.Construction.RealizationPrism.interior_mem_subcomplex_iffline 409Source documentation
A subcomplex contains a point of a simplex interior exactly when it contains the simplex itself.
theorem interior_mem_subcomplex_iff (K : SSet.{0}) (A : K.Subcomplex) {n : ℕ} (s : K.obj (.op (.mk n))) (x : StdSimplex ℝ (Fin (n+1))) (hx : x ∈ fullSupport n) : simplexPoint K s x ∈ Set.range (SSet.toTop.map A.ι).hom ↔ s ∈ A.obj _ := by …Mentions: OAI.Thomason.Construction.RealizationPrism.fullSupport, OAI.Thomason.Construction.RealizationPrism.simplexPoint
- theorem
OAI.Thomason.Construction.RealizationPrism.boundary_point_dimension_ltline 417Source documentation
Boundary points of an
n-simplex belong to cells of strictly smaller dimension, including when the original simplex or its faces are degenerate.theorem boundary_point_dimension_lt (K : SSet.{0}) {n : ℕ} (s : K.obj (.op (.mk n))) (x : StdSimplex ℝ (Fin (n+1))) (hx : x ∈ boundaryLocus n) : (normalization K (simplexPoint K s x)).1.dim < n := by …Mentions: OAI.Thomason.Construction.RealizationPrism.boundaryLocus, OAI.Thomason.Construction.RealizationPrism.normalization, OAI.Thomason.Construction.RealizationPrism.simplexPoint
- theorem
OAI.Thomason.Construction.RealizationPrism.cellBoundaryMap_dimension_ltline 428Source documentation
The actual attaching map lands entirely in lower-dimensional cells.
theorem cellBoundaryMap_dimension_lt (K : SSet.{0}) {n : ℕ} (s : K.obj (.op (.mk n))) (x : SSet.toTop.obj (SSet.boundary n : SSet.{0})) : (normalization K ((cellBoundaryMap K s).hom x)).1.dim < n := by …Mentions: OAI.Thomason.Construction.RealizationPrism.normalization, OAI.Thomason.Construction.RealizationPrism.cellBoundaryMap
- abbrev
OAI.Thomason.Construction.RealizationPrism.simplicialBoundaryCellline 460 - abbrev
OAI.Thomason.Construction.RealizationPrism.realizedBoundaryCellline 462 - abbrev
OAI.Thomason.Construction.RealizationPrism.barycentricBoundaryCellline 464 - def
OAI.Thomason.Construction.RealizationPrism.realizeBoundaryAttachmentline 468Source documentation
Realization carries a simultaneous simplicial boundary attachment to the corresponding simultaneous topological attachment.
def realizeBoundaryAttachment {X Y : SSet.{0}} {n : ℕ} {f : X ⟶ Y} (c : AttachCells.{0} (simplicialBoundaryCell n) f) : AttachCells.{0} (realizedBoundaryCell n) (SSet.toTop.map f) where …Mentions: OAI.Thomason.Construction.RealizationPrism.simplicialBoundaryCell, OAI.Thomason.Construction.RealizationPrism.realizedBoundaryCell
- def
OAI.Thomason.Construction.RealizationPrism.realizedCellComplexOfMonoline 490Source documentation
The topological skeletal presentation with the original realized boundary arrows.
def realizedCellComplexOfMono {X Y : SSet.{0}} (i : X ⟶ Y) [Mono i] : RelativeCellComplex.{0} realizedBoundaryCell (SSet.toTop.map i) := by …Mentions: OAI.Thomason.Construction.RealizationPrism.realizedBoundaryCell
- def
OAI.Thomason.Construction.RealizationPrism.barycentricCellComplexOfMonoline 501Source documentation
Every realized monomorphism is obtained by attaching actual barycentric
n-simplices along their boundaries at stagen.def barycentricCellComplexOfMono {X Y : SSet.{0}} (i : X ⟶ Y) [Mono i] : RelativeCellComplex.{0} barycentricBoundaryCell (SSet.toTop.map i) where …Mentions: OAI.Thomason.Construction.RealizationPrism.barycentricBoundaryCell
- theorem
OAI.Thomason.Construction.RealizationPrism.mem_range_iff_normalizationline 527Source documentation
Subcomplex membership can be tested on the unique nondegenerate interior representative of the point.
theorem mem_range_iff_normalization (K : SSet.{0}) (A : K.Subcomplex) (x : SSet.toTop.obj K) : x ∈ Set.range (SSet.toTop.map A.ι).hom ↔ (normalization K x).1.simplex ∈ A.obj _ := by …Mentions: OAI.Thomason.Construction.RealizationPrism.normalization
- theorem
OAI.Thomason.Construction.RealizationPrism.range_iSup_inclusionline 540Source documentation
Realization carries an arbitrary subcomplex union to the literal union of the corresponding topological subspaces.
theorem range_iSup_inclusion (K : SSet.{0}) {ι : Type} (A : ι → K.Subcomplex) : Set.range (SSet.toTop.map (iSup A).ι).hom = ⋃ i, Set.range (SSet.toTop.map (A i).ι).hom := by … - theorem
OAI.Thomason.Construction.RealizationPrism.range_realized_mapline 550Source documentation
The actual point-set image of a realized simplicial map is exactly the realization of its simplicial image subcomplex.
theorem range_realized_map {K L : SSet.{0}} (f : K ⟶ L) : Set.range (SSet.toTop.map f).hom = Set.range (SSet.toTop.map (SSet.Subcomplex.range f).ι).hom := by … - theorem
OAI.Thomason.Construction.RealizationPrism.compact_subset_stageline 585Source documentation
A compact subset of an exhausted realization lies in one actual stage. The proof bounds its finitely many intrinsic carriers simultaneously.
theorem compact_subset_stage (K : SSet.{0}) (A : ℕ → K.Subcomplex) (hA : Monotone A) (hcover : iSup A = ⊤) (C : Set (SSet.toTop.obj K)) (hC : IsCompact C) : ∃ n, C ⊆ Set.range (SSet.toTop.map (A n).ι).hom := by … - theorem
OAI.Thomason.Construction.RealizationPrism.compact_map_factors_stageline 615Source documentation
Every compact continuous map factors continuously through a single stage, with exact equality after the actual inclusion.
theorem compact_map_factors_stage {P : Type} [TopologicalSpace P] [CompactSpace P] (K : SSet.{0}) (A : ℕ → K.Subcomplex) (hA : Monotone A) (hcover : iSup A = ⊤) (f : C(P, SSet.toTop.obj K)) : ∃ (n : ℕ) (g : C(P, SSet.toTop.obj (A n : SSet))), (SSet.toTop.map (A n).ι).hom.comp g = f := by … - theorem
OAI.Thomason.Construction.RealizationPrism.compact_map_factors_stage_afterline 633Source documentation
The stage can be chosen beyond any previously fixed stage.
theorem compact_map_factors_stage_after {P : Type} [TopologicalSpace P] [CompactSpace P] (K : SSet.{0}) (A : ℕ → K.Subcomplex) (hA : Monotone A) (hcover : iSup A = ⊤) (m : ℕ) (f : C(P, SSet.toTop.obj K)) : ∃ (n : ℕ), m ≤ n ∧ ∃ g : C(P, SSet.toTop.obj (A n : SSet)), (SSet.toTop.map (A n).ι).hom.comp g = f := by … - theorem
OAI.Thomason.Construction.RealizationPrism.compact_pair_factors_stageline 651Source documentation
Two compact maps with unrelated domains have a common stage. This also synchronizes point representatives of different path components.
theorem compact_pair_factors_stage {P Q : Type} [TopologicalSpace P] [CompactSpace P] [TopologicalSpace Q] [CompactSpace Q] (K : SSet.{0}) (A : ℕ → K.Subcomplex) (hA : Monotone A) (hcover : iSup A = ⊤) (f : C(P, SSet.toTop.obj K)) (g : C(Q, SSet.toTop.obj K)) : ∃ (n : ℕ) (f' : C(P, SSet.toTop.obj (A n : SSet))) (g' : C(Q, SSet.toTop.obj (A n : SSet))), (SSet.toTop.map (A n).ι).hom.comp f' = f ∧ (SSet.toTop.map (A n).ι).hom.comp g' = g := by … - theorem
OAI.Thomason.Construction.RealizationPrism.based_cube_factors_stageline 697Source documentation
A based cube whose basepoint is already in one stage lifts to a later stage with that same basepoint and its entire boundary fixed.
theorem based_cube_factors_stage (K : SSet.{0}) (A : ℕ → K.Subcomplex) (hA : Monotone A) (hcover : iSup A = ⊤) (m : ℕ) (x : SSet.toTop.obj (A m : SSet)) (d : ℕ) (p : GenLoop (Fin d) (SSet.toTop.obj K) ((SSet.toTop.map (A m).ι).hom x)) : ∃ (n : ℕ) (hn : m ≤ n), ∃ q : GenLoop (Fin d) (SSet.toTop.obj (A n : SSet)) ((SSet.toTop.map (SSet.Subcomplex.homOfLE (hA hn))).hom x), ∀ t, (SSet.toTop.map (A n).ι).hom (q t) = p t := by … - theorem
OAI.Thomason.Construction.RealizationPrism.based_homotopy_factors_stageline 719Source documentation
A homotopy between two cubes in one stage is already a homotopy in a later stage, with the original endpoint cubes and whole boundary retained.
theorem based_homotopy_factors_stage (K : SSet.{0}) (A : ℕ → K.Subcomplex) (hA : Monotone A) (hcover : iSup A = ⊤) (m : ℕ) (x : SSet.toTop.obj (A m : SSet)) (d : ℕ) (p q : GenLoop (Fin d) (SSet.toTop.obj (A m : SSet)) x) (H : (HomotopyMaps.loopMap (SSet.toTop.map (A m).ι).hom p).val.HomotopyRel (HomotopyMaps.loopMap (SSet.toTop.map (A m).ι).hom q).val (Cube.boundary (Fin d))) : ∃ (n : ℕ) (hn : m ≤ n), Nonempty ((HomotopyMaps.loopMap (SSet.toTop.map (SSet.Subcomplex.homOfLE (hA hn))).hom p).val.HomotopyRel (HomotopyMaps.loopMap (SSet.toTop.map (SSet.Subcomplex.homOfLE (hA hn))).hom q).val (Cube.boundary (Fin d))) := by … - theorem
OAI.Thomason.Construction.RealizationPrism.homotopyGroup_eventual_eqline 753Source documentation
Equality of homotopy classes in the exhausted realization is witnessed in one later stage, retaining the original chosen basepoint.
theorem homotopyGroup_eventual_eq (K : SSet.{0}) (A : ℕ → K.Subcomplex) (hA : Monotone A) (hcover : iSup A = ⊤) (m : ℕ) (x : SSet.toTop.obj (A m : SSet)) (d : ℕ) (a b : HomotopyGroup.Pi d (SSet.toTop.obj (A m : SSet)) x) (hab : HomotopyMaps.groupMap (SSet.toTop.map (A m).ι).hom d x a = HomotopyMaps.groupMap (SSet.toTop.map (A m).ι).hom d x b) : ∃ (n : ℕ) (hn : m ≤ n), HomotopyMaps.groupMap (SSet.toTop.map (SSet.Subcomplex.homOfLE (hA hn))).hom d x a = HomotopyMaps.groupMap (SSet.toTop.map (SSet.Subcomplex.homOfLE (hA hn))).hom d x b := by … - theorem
OAI.Thomason.Construction.RealizationPrism.components_eventual_eqline 773Source documentation
Equality of components also occurs at a finite stage.
theorem components_eventual_eq (K : SSet.{0}) (A : ℕ → K.Subcomplex) (hA : Monotone A) (hcover : iSup A = ⊤) (m : ℕ) (a b : ZerothHomotopy (SSet.toTop.obj (A m : SSet))) (hab : HomotopyMaps.componentsMap (SSet.toTop.map (A m).ι).hom a = HomotopyMaps.componentsMap (SSet.toTop.map (A m).ι).hom b) : ∃ (n : ℕ) (hn : m ≤ n), HomotopyMaps.componentsMap (SSet.toTop.map (SSet.Subcomplex.homOfLE (hA hn))).hom a = HomotopyMaps.componentsMap (SSet.toTop.map (SSet.Subcomplex.homOfLE (hA hn))).hom b := by …Mentions: OAI.Thomason.Construction.HomotopyMaps.componentsMap
- theorem
OAI.Thomason.Construction.RealizationPrism.based_pair_factors_stageline 807Source documentation
A pair of based cubes can be placed in the same stage, beyond the stage of their specified basepoint. Both cubes retain their entire boundary.
theorem based_pair_factors_stage (K : SSet.{0}) (A : ℕ → K.Subcomplex) (hA : Monotone A) (hcover : iSup A = ⊤) (m : ℕ) (x : SSet.toTop.obj (A m : SSet)) (d : ℕ) (p q : GenLoop (Fin d) (SSet.toTop.obj K) ((SSet.toTop.map (A m).ι).hom x)) : ∃ (n : ℕ) (hn : m ≤ n), ∃ p' q' : GenLoop (Fin d) (SSet.toTop.obj (A n : SSet)) ((SSet.toTop.map (SSet.Subcomplex.homOfLE (hA hn))).hom x), (∀ t, (SSet.toTop.map (A n).ι).hom (p' t) = p t) ∧ (∀ t, (SSet.toTop.map (A n).ι).hom (q' t) = q t) := by … - theorem
OAI.Thomason.Construction.RealizationPrism.exhaustion_initial_weakline 868Source documentation
If the inclusion of the initial stage into every stage is weak, then its inclusion into the exhausted realization is weak. Compact cubes and relative homotopies provide the required finite-stage witnesses.
theorem exhaustion_initial_weak (K : SSet.{0}) (A : ℕ → K.Subcomplex) (hA : Monotone A) (hcover : iSup A = ⊤) (hW : ∀ n, realizationWeakEquivalences (SSet.Subcomplex.homOfLE (hA (Nat.zero_le n)))) : realizationWeakEquivalences (A 0).ι := by …Mentions: OAI.Thomason.Construction.realizationWeakEquivalences
- theorem
OAI.Thomason.Construction.RealizationPrism.exhaustion_weak_of_successorline 946Source documentation
Successive weak inclusions in a simplicial exhaustion induce a weak inclusion of its initial stage into the whole realization.
theorem exhaustion_weak_of_successor (K : SSet.{0}) (A : ℕ → K.Subcomplex) (hA : Monotone A) (hcover : iSup A = ⊤) (hW : ∀ n, realizationWeakEquivalences (SSet.Subcomplex.homOfLE (hA (Nat.le_succ n)))) : realizationWeakEquivalences (A 0).ι := by …Mentions: OAI.Thomason.Construction.realizationWeakEquivalences