Definitions for Simplicial principal bundles in parametrized spaces
DefinitionQAlgorithms_Papers_Independent_Intakethird100_P73The objects the formalized statements of Simplicial principal bundles in parametrized spaces (arXiv:1203.2460) are stated in. Each was checked against the paper by a blind read-back and a moderator.
KSpace: A k-space, without a separation axiom (PDF p. 2).kify: Kification, using the final topology for all compact Hausdorff probes (PDF p. 4, all products and limits are in K).kifyProjection: The identity map from the kification to the original space.kifyProbe: A compact Hausdorff probe is continuous into the kification by its definition.kifyMap: Kification of a continuous map; neither topology is silently discarded.IsWeaklyHausdorff: Weak Hausdorffness means that every compact Hausdorff probe has closed image (PDF p. 2). This does not require Hausdorffness.SpaceOver: An object of K/B (PDF p. 2).MapOver: A continuous map over the fixed base (PDF p. 2).identityOver: Identity morphism over B.composeOver: Composition of morphisms over B, in functional order.FiberProductSet: The underlying set of a fiber product, with its ordinary subspace topology only as the input to kification. It is not used as the categorical product.fiberProductOver: The actual fiber product over B with k-space topology (PDF pp. 4--5).fiberProductSetMap: The map of underlying pullback subspaces induced by two maps over B.fiberProductMap: Product of two given maps, with both pullback topologies kified. This is the product map, not the pushout-product (PDF p. 20).FiberwiseHomotopic: Fiberwise homotopy: a continuous homotopy on the kified tensor X times I, with both endpoints specified and the projection fixed for every time (PDF pp. 4--5).IsFEquivalence: An f-equivalence has an inverse over B and two fiberwise homotopies, not merely homotopy equivalences on separate fibers (PDF p. 5).IsFFibration: The fiberwise covering homotopy property, for every test object in K/B (PDF p. 5). The entire lift is over B.IsStrongFCofibration: Strong fbar-cofibrations have the LLP against all f-acyclic f-fibrations in K/B. Neither f-cofibrations nor NDR representations are substituted for this definition (PDF p. 5).fiberPair: A point of the kified fiber product, retaining the common-base equation.ParametrizedGroup: A group object in K/B, with continuous unit, multiplication, and inverse and all group axioms on each common fiber (PDF pp. 2, 5--6).EquivariantSpace: A continuous right action over B; its domain is a kified fiber product, not the Cartesian product of possibly different fibers (PDF p. 6).EquivariantMap: A G-equivariant map over B (PDF p. 6).equivariantIdentity: Identity G-map.equivariantCompose: Composite G-map in functional order.EquivariantCylinderMap: A G-map X tensor I to Y. Equivariance is required at every time, with G acting trivially on I, and the homotopy stays over B (PDF pp. 6--7).EquivariantlyHomotopic: Homotopy through G-maps over B with the specified endpoints (PDF p. 7).IsEquivariantFEquivalence: An equivariant f-equivalence includes an equivariant inverse and both homotopies over B (PDF p. 7).IsEquivariantFFibration: The equivariant covering homotopy property for every G-space over B (PDF p. 7).IsEquivariantStrongFCofibration: The LLP in G K/B against all equivariant f-acyclic f-fibrations (PDF p. 7). This is stronger than a condition only on underlying maps.IsEquivariantFiberwiseNDR: The source's right-equivariant fiberwise NDR condition (PDF pp. 5, 7). The zero set is exactly A, A is fixed for all times, and only u(x) < 1 requires the terminal homotopy value to lie in A.GroupMapOver: A continuous homomorphism of parametrized groups (PDF pp. 2, 8). Preservation of inverses follows from these group homomorphism axioms.SimplicialParametrizedGroup: A simplicial parametrized group is contravariant functor data on the whole simplex category, taking every arrow to a continuous homomorphism. The identity and composition equations specify the full simplicial object; levels are not arbitrary unrelated groups (PDF p. 2).constantSimplicialGroup: The constant simplicial parametrized group, for a sanity check.baseOver: The terminal object B→B, which is the domain of the identity section.groupUnitSection: The canonical identity section as a map over B (PDF pp. 5--6).IsWellSectioned: Well-sectionedness is the strong cofibration property of the canonical identity section, not an arbitrary supplied section (Definition 6, PDF p. 6).IsGoodSimplicialGroup: Goodness requires every degeneracy in every degree to be a strong fbar-cofibration (Definition 20, PDF p. 12).
import Mathlib
/-!
Local definitions for Roberts--Stevenson, arXiv:1203.2460v4, PDF pp. 2, 4--5, 20.
Products below have the compactly generated topology. No weak Hausdorff
condition is imposed on total spaces. The other planned nodes are explicitly
deferred in this paper's HARD.md and GAPS.json, rather than weakened.
-/
noncomputable section
universe u
namespace QAlgorithms.Papers.Independent.Intakethird100.P73
open CategoryTheory
open scoped Topology
/-- A k-space, without a separation axiom (PDF p. 2). -/
structure KSpace where
Carrier : Type u
topology : TopologicalSpace Carrier
generated : @CompactlyGeneratedSpace Carrier topology
/-- Use the carrier of the bundled k-space, without changing its topology. -/
instance kSpaceCoeSort : CoeSort KSpace.{u} (Type u) := ⟨KSpace.Carrier⟩
/-- Recover exactly the topology stored in the bundled k-space. -/
instance kSpaceTopology (X : KSpace.{u}) : TopologicalSpace X := X.topology
/-- Recover the compact-generation witness for that same stored topology. -/
instance kSpaceCompactlyGenerated (X : KSpace.{u}) : CompactlyGeneratedSpace X := X.generated
/-- Kification, using the final topology for all compact Hausdorff probes
(PDF p. 4, all products and limits are in K). -/
def kify (X : Type u) [TopologicalSpace X] : KSpace where
Carrier := X
topology := TopologicalSpace.compactlyGenerated.{u} X
generated := by
let T := Σ i : (S : CompHaus.{u}) × C(S, X), i.fst
let q : T → X := fun z => z.1.2 z.2
letI : TopologicalSpace X := TopologicalSpace.compactlyGenerated.{u} X
exact uCompactlyGeneratedSpace_of_coinduced (f := q) continuous_coinduced_rng rfl
/-- The identity map from the kification to the original space. -/
def kifyProjection (X : Type u) [tX : TopologicalSpace X] : C(kify X, X) where
toFun := id
continuous_toFun := by
change Continuous[TopologicalSpace.compactlyGenerated.{u} X, tX] (id : X → X)
exact @continuous_from_compactlyGenerated.{u, u, u} X X tX tX id
(fun _ g => g.continuous)
/-- A compact Hausdorff probe is continuous into the kification by its definition. -/
def kifyProbe {X : Type u} [TopologicalSpace X] (S : CompHaus.{u})
(f : C(S, X)) : C(S, kify X) where
toFun := f
continuous_toFun := by
change Continuous[inferInstance, TopologicalSpace.coinduced
(fun z : (Σ i : (T : CompHaus.{u}) × C(T, X), i.fst) => z.1.2 z.2)
inferInstance] (f : S → X)
let T := Σ i : (U : CompHaus.{u}) × C(U, X), i.fst
let q : T → X := fun z => z.1.2 z.2
let j : S → T := fun s => ⟨⟨S, f⟩, s⟩
have hj : Continuous j := continuous_sigmaMk
(σ := fun i : (U : CompHaus.{u}) × C(U, X) => (i.fst : Type u))
(i := (⟨S, f⟩ : (U : CompHaus.{u}) × C(U, X)))
exact @Continuous.comp S T X inferInstance inferInstance
(TopologicalSpace.coinduced q inferInstance) j q
(continuous_coinduced_rng (f := q) (t := inferInstance)) hj
/-- Kification of a continuous map; neither topology is silently discarded. -/
def kifyMap {X Y : Type u} [tX : TopologicalSpace X] [tY : TopologicalSpace Y]
(f : C(X, Y)) : C(kify X, kify Y) where
toFun := f
continuous_toFun := by
change Continuous[TopologicalSpace.compactlyGenerated.{u} X,
TopologicalSpace.compactlyGenerated.{u} Y] (f : X → Y)
exact @continuous_from_compactlyGenerated.{u, u, u} X Y tX
(TopologicalSpace.compactlyGenerated.{u} Y) (f : X → Y)
(fun S g => (kifyProbe S (f.comp g)).continuous)
/-- Weak Hausdorffness means that every compact Hausdorff probe has closed image
(PDF p. 2). This does not require Hausdorffness. -/
def IsWeaklyHausdorff (B : KSpace.{u}) : Prop :=
∀ (S : CompHaus.{u}) (f : C(S, B)), IsClosed (Set.range f)
/-- An object of K/B (PDF p. 2). -/
structure SpaceOver (B : KSpace.{u}) where
space : KSpace.{u}
projection : C(space, B)
/-- A continuous map over the fixed base (PDF p. 2). -/
structure MapOver {B : KSpace} (X Y : SpaceOver B) where
map : C(X.space, Y.space)
over_base : ∀ x, Y.projection (map x) = X.projection x
/-- Identity morphism over B. -/
def identityOver {B : KSpace} (X : SpaceOver B) : MapOver X X where
map := ContinuousMap.id X.space
over_base := fun _ => rfl
/-- Composition of morphisms over B, in functional order. -/
def composeOver {B : KSpace} {X Y Z : SpaceOver B}
(g : MapOver Y Z) (f : MapOver X Y) : MapOver X Z where
map := g.map.comp f.map
over_base := fun x => (g.over_base (f.map x)).trans (f.over_base x)
/-- The underlying set of a fiber product, with its ordinary subspace topology
only as the input to kification. It is not used as the categorical product. -/
abbrev FiberProductSet {B : KSpace} (X Y : SpaceOver B) :=
{z : X.space × Y.space // X.projection z.1 = Y.projection z.2}
/-- The actual fiber product over B with k-space topology (PDF pp. 4--5). -/
def fiberProductOver {B : KSpace} (X Y : SpaceOver B) : SpaceOver B where
space := kify (FiberProductSet X Y)
projection :=
(⟨fun z : FiberProductSet X Y => X.projection z.val.1, by fun_prop⟩ :
C(FiberProductSet X Y, B)).comp (kifyProjection (FiberProductSet X Y))
/-- The map of underlying pullback subspaces induced by two maps over B. -/
def fiberProductSetMap {B : KSpace} {A X D Y : SpaceOver B}
(f : MapOver A X) (g : MapOver D Y) :
C(FiberProductSet A D, FiberProductSet X Y) where
toFun := fun z => ⟨(f.map z.val.1, g.map z.val.2),
(f.over_base z.val.1).trans (z.property.trans (g.over_base z.val.2).symm)⟩
continuous_toFun := by fun_prop
/-- Product of two given maps, with both pullback topologies kified.
This is the product map, not the pushout-product (PDF p. 20). -/
def fiberProductMap {B : KSpace} {A X D Y : SpaceOver B}
(f : MapOver A X) (g : MapOver D Y) :
MapOver (fiberProductOver A D) (fiberProductOver X Y) where
map := kifyMap (fiberProductSetMap f g)
over_base := fun z => f.over_base z.val.1
/-- Fiberwise homotopy: a continuous homotopy on the kified tensor X times I,
with both endpoints specified and the projection fixed for every time
(PDF pp. 4--5). -/
def FiberwiseHomotopic {B : KSpace} {X Y : SpaceOver B}
(f g : MapOver X Y) : Prop :=
∃ H : C(kify (X.space × unitInterval), Y.space),
(∀ x, H (x, 0) = f.map x) ∧
(∀ x, H (x, 1) = g.map x) ∧
∀ x t, Y.projection (H (x, t)) = X.projection x
/-- An f-equivalence has an inverse over B and two fiberwise homotopies,
not merely homotopy equivalences on separate fibers (PDF p. 5). -/
def IsFEquivalence {B : KSpace} {X Y : SpaceOver B} (f : MapOver X Y) : Prop :=
∃ g : MapOver Y X,
FiberwiseHomotopic (composeOver g f) (identityOver X) ∧
FiberwiseHomotopic (composeOver f g) (identityOver Y)
/-- The fiberwise covering homotopy property, for every test object in K/B
(PDF p. 5). The entire lift is over B. -/
def IsFFibration {B : KSpace} {X Y : SpaceOver B} (p : MapOver X Y) : Prop :=
∀ (Z : SpaceOver B) (a : MapOver Z X)
(H : C(kify (Z.space × unitInterval), Y.space)),
(∀ z t, Y.projection (H (z, t)) = Z.projection z) →
(∀ z, H (z, 0) = p.map (a.map z)) →
∃ L : C(kify (Z.space × unitInterval), X.space),
(∀ z t, X.projection (L (z, t)) = Z.projection z) ∧
(∀ z, L (z, 0) = a.map z) ∧
∀ z t, p.map (L (z, t)) = H (z, t)
/-- Strong fbar-cofibrations have the LLP against all f-acyclic f-fibrations
in K/B. Neither f-cofibrations nor NDR representations are substituted for
this definition (PDF p. 5). -/
def IsStrongFCofibration {B : KSpace} {A X : SpaceOver B} (i : MapOver A X) : Prop :=
∀ (U V : SpaceOver B) (p : MapOver U V),
IsFFibration p → IsFEquivalence p →
∀ (a : MapOver A U) (b : MapOver X V),
(∀ z, p.map (a.map z) = b.map (i.map z)) →
∃ l : MapOver X U,
(∀ z, l.map (i.map z) = a.map z) ∧
∀ x, p.map (l.map x) = b.map x
/-- Sanity: identity maps have the stated lifting property. -/
example {B : KSpace} (X : SpaceOver B) :
IsStrongFCofibration (identityOver X) := by
intro U V p hp he a b h
exact ⟨a, fun _ => rfl, h⟩
/-- Sanity: the product map acts on both coordinates, with no union or
pushout-product hidden in its definition. -/
example {B : KSpace} {A X D Y : SpaceOver B} (f : MapOver A X) (g : MapOver D Y)
(z : (fiberProductOver A D).space) :
((fiberProductMap f g).map z).val = (f.map z.val.1, g.map z.val.2) := by
rfl
/-- A point of the kified fiber product, retaining the common-base equation. -/
def fiberPair {B : KSpace} {X Y : SpaceOver B} (x : X.space) (y : Y.space)
(h : X.projection x = Y.projection y) : (fiberProductOver X Y).space :=
⟨(x, y), h⟩
/-- A group object in K/B, with continuous unit, multiplication, and inverse
and all group axioms on each common fiber (PDF pp. 2, 5--6). -/
structure ParametrizedGroup (B : KSpace) where
total : SpaceOver B
unit : C(B, total.space)
unit_over : ∀ b, total.projection (unit b) = b
multiply : MapOver (fiberProductOver total total) total
inverse : MapOver total total
left_unit : ∀ g, multiply.map
(fiberPair (unit (total.projection g)) g (unit_over _)) = g
right_unit : ∀ g, multiply.map
(fiberPair g (unit (total.projection g)) (unit_over _).symm) = g
left_inverse : ∀ g, multiply.map
(fiberPair (inverse.map g) g (inverse.over_base g)) = unit (total.projection g)
right_inverse : ∀ g, multiply.map
(fiberPair g (inverse.map g) (inverse.over_base g).symm) = unit (total.projection g)
associative : ∀ g h k (hgh : total.projection g = total.projection h)
(hhk : total.projection h = total.projection k),
multiply.map (fiberPair (multiply.map (fiberPair g h hgh)) k
((multiply.over_base (fiberPair g h hgh)).trans (hgh.trans hhk))) =
multiply.map (fiberPair g (multiply.map (fiberPair h k hhk))
(hgh.trans (multiply.over_base (fiberPair h k hhk)).symm))
/-- Sanity: every base admits the trivial parametrized group, whose fibers
are singletons. This also covers the empty base. -/
example (B : KSpace) : Nonempty (ParametrizedGroup B) := by
let T : SpaceOver B := ⟨B, ContinuousMap.id B⟩
let m : MapOver (fiberProductOver T T) T :=
{ map := (⟨fun z : FiberProductSet T T => z.val.1, by fun_prop⟩ :
C(FiberProductSet T T, B)).comp (kifyProjection (FiberProductSet T T))
over_base := fun _ => rfl }
exact ⟨{ total := T
unit := ContinuousMap.id B
unit_over := fun _ => rfl
multiply := m
inverse := identityOver T
left_unit := fun _ => rfl
right_unit := fun _ => rfl
left_inverse := fun _ => rfl
right_inverse := fun _ => rfl
associative := fun _ _ _ _ _ => rfl }⟩
/-- A continuous right action over B; its domain is a kified fiber product,
not the Cartesian product of possibly different fibers (PDF p. 6). -/
structure EquivariantSpace {B : KSpace} (G : ParametrizedGroup B) where
total : SpaceOver B
action : MapOver (fiberProductOver total G.total) total
action_unit : ∀ x, action.map
(fiberPair x (G.unit (total.projection x)) (G.unit_over _).symm) = x
action_multiply : ∀ x g h (hxg : total.projection x = G.total.projection g)
(hgh : G.total.projection g = G.total.projection h),
action.map (fiberPair (action.map (fiberPair x g hxg)) h
((action.over_base (fiberPair x g hxg)).trans (hxg.trans hgh))) =
action.map (fiberPair x (G.multiply.map (fiberPair g h hgh))
(hxg.trans (G.multiply.over_base (fiberPair g h hgh)).symm))
/-- A G-equivariant map over B (PDF p. 6). -/
structure EquivariantMap {B : KSpace} {G : ParametrizedGroup B}
(X Y : EquivariantSpace G) where
map : MapOver X.total Y.total
equivariant : ∀ x g (h : X.total.projection x = G.total.projection g),
map.map (X.action.map (fiberPair x g h)) =
Y.action.map (fiberPair (map.map x) g ((map.over_base x).trans h))
/-- Identity G-map. -/
def equivariantIdentity {B : KSpace} {G : ParametrizedGroup B}
(X : EquivariantSpace G) : EquivariantMap X X where
map := identityOver X.total
equivariant := fun _ _ _ => rfl
/-- Composite G-map in functional order. -/
def equivariantCompose {B : KSpace} {G : ParametrizedGroup B}
{X Y Z : EquivariantSpace G} (g : EquivariantMap Y Z) (f : EquivariantMap X Y) :
EquivariantMap X Z where
map := composeOver g.map f.map
equivariant := by
intro x a h
change g.map.map (f.map.map (X.action.map (fiberPair x a h))) = _
rw [f.equivariant, g.equivariant]
rfl
/-- A G-map X tensor I to Y. Equivariance is required at every time,
with G acting trivially on I, and the homotopy stays over B (PDF pp. 6--7). -/
structure EquivariantCylinderMap {B : KSpace} {G : ParametrizedGroup B}
(X Y : EquivariantSpace G) where
map : C(kify (X.total.space × unitInterval), Y.total.space)
over_base : ∀ x t, Y.total.projection (map (x, t)) = X.total.projection x
equivariant : ∀ x g (h : X.total.projection x = G.total.projection g) t,
map (X.action.map (fiberPair x g h), t) =
Y.action.map (fiberPair (map (x, t)) g ((over_base x t).trans h))
/-- Homotopy through G-maps over B with the specified endpoints (PDF p. 7). -/
def EquivariantlyHomotopic {B : KSpace} {G : ParametrizedGroup B}
{X Y : EquivariantSpace G} (f g : EquivariantMap X Y) : Prop :=
∃ H : EquivariantCylinderMap X Y,
(∀ x, H.map (x, 0) = f.map.map x) ∧
∀ x, H.map (x, 1) = g.map.map x
/-- An equivariant f-equivalence includes an equivariant inverse and both
homotopies over B (PDF p. 7). -/
def IsEquivariantFEquivalence {B : KSpace} {G : ParametrizedGroup B}
{X Y : EquivariantSpace G} (f : EquivariantMap X Y) : Prop :=
∃ g : EquivariantMap Y X,
EquivariantlyHomotopic (equivariantCompose g f) (equivariantIdentity X) ∧
EquivariantlyHomotopic (equivariantCompose f g) (equivariantIdentity Y)
/-- The equivariant covering homotopy property for every G-space over B
(PDF p. 7). -/
def IsEquivariantFFibration {B : KSpace} {G : ParametrizedGroup B}
{X Y : EquivariantSpace G} (p : EquivariantMap X Y) : Prop :=
∀ (Z : EquivariantSpace G) (a : EquivariantMap Z X)
(H : EquivariantCylinderMap Z Y),
(∀ z, H.map (z, 0) = p.map.map (a.map.map z)) →
∃ L : EquivariantCylinderMap Z X,
(∀ z, L.map (z, 0) = a.map.map z) ∧
∀ z t, p.map.map (L.map (z, t)) = H.map (z, t)
/-- The LLP in G K/B against all equivariant f-acyclic f-fibrations
(PDF p. 7). This is stronger than a condition only on underlying maps. -/
def IsEquivariantStrongFCofibration {B : KSpace} {G : ParametrizedGroup B}
{A X : EquivariantSpace G} (i : EquivariantMap A X) : Prop :=
∀ (U V : EquivariantSpace G) (p : EquivariantMap U V),
IsEquivariantFFibration p → IsEquivariantFEquivalence p →
∀ (a : EquivariantMap A U) (b : EquivariantMap X V),
(∀ z, p.map.map (a.map.map z) = b.map.map (i.map.map z)) →
∃ l : EquivariantMap X U,
(∀ z, l.map.map (i.map.map z) = a.map.map z) ∧
∀ x, p.map.map (l.map.map x) = b.map.map x
/-- The source's right-equivariant fiberwise NDR condition (PDF pp. 5, 7).
The zero set is exactly A, A is fixed for all times, and only u(x) < 1
requires the terminal homotopy value to lie in A. -/
def IsEquivariantFiberwiseNDR {B : KSpace} {G : ParametrizedGroup B}
(X : EquivariantSpace G) (A : Set X.total.space) : Prop :=
∃ u : C(X.total.space, unitInterval),
∃ H : EquivariantCylinderMap X X,
(∀ x, x ∈ A ↔ u x = 0) ∧
(∀ x, H.map (x, 0) = x) ∧
(∀ x ∈ A, ∀ t, H.map (x, t) = x) ∧
(∀ x, (u x : ℝ) < 1 → H.map (x, 1) ∈ A) ∧
∀ x g (h : X.total.projection x = G.total.projection g),
u (X.action.map (fiberPair x g h)) = u x
/-- Sanity: the identity G-map satisfies the equivariant LLP. -/
example {B : KSpace} {G : ParametrizedGroup B} (X : EquivariantSpace G) :
IsEquivariantStrongFCofibration (equivariantIdentity X) := by
intro U V p hp he a b h
exact ⟨a, fun _ => rfl, h⟩
/-- Sanity: the whole space is an NDR subspace, using u = 0 and the
constant-in-time equivariant fiberwise homotopy. -/
example {B : KSpace} {G : ParametrizedGroup B} (X : EquivariantSpace G) :
IsEquivariantFiberwiseNDR X Set.univ := by
let H : EquivariantCylinderMap X X :=
{ map := ContinuousMap.fst.comp (kifyProjection (X.total.space × unitInterval))
over_base := fun _ _ => rfl
equivariant := fun _ _ _ _ => rfl }
refine ⟨ContinuousMap.const _ 0, H, ?_, ?_, ?_, ?_, ?_⟩
· intro x
simp
· intro x
rfl
· intro x hx t
rfl
· intro x hx
trivial
· intro x g h
rfl
/-- A continuous homomorphism of parametrized groups (PDF pp. 2, 8).
Preservation of inverses follows from these group homomorphism axioms. -/
structure GroupMapOver {B : KSpace} (G H : ParametrizedGroup B) where
map : MapOver G.total H.total
unit_preserved : ∀ b, map.map (G.unit b) = H.unit b
multiply_preserved : ∀ g h (e : G.total.projection g = G.total.projection h),
map.map (G.multiply.map (fiberPair g h e)) =
H.multiply.map (fiberPair (map.map g) (map.map h)
((map.over_base g).trans (e.trans (map.over_base h).symm)))
/-- A simplicial parametrized group is contravariant functor data on the
whole simplex category, taking every arrow to a continuous homomorphism.
The identity and composition equations specify the full simplicial object;
levels are not arbitrary unrelated groups (PDF p. 2). -/
structure SimplicialParametrizedGroup (B : KSpace) where
obj : SimplexCategoryᵒᵖ → ParametrizedGroup B
map : ∀ {a b : SimplexCategoryᵒᵖ}, (a ⟶ b) → GroupMapOver (obj a) (obj b)
map_identity : ∀ (a : SimplexCategoryᵒᵖ) (x : (obj a).total.space),
(map (𝟙 a)).map.map x = x
map_composition : ∀ {a b c : SimplexCategoryᵒᵖ} (f : a ⟶ b) (g : b ⟶ c)
(x : (obj a).total.space),
(map (f ≫ g)).map.map x =
(map g).map.map ((map f).map.map x)
/-- The constant simplicial parametrized group, for a sanity check. -/
def constantSimplicialGroup {B : KSpace} (G : ParametrizedGroup B) :
SimplicialParametrizedGroup B where
obj := fun _ => G
map := fun _ =>
{ map := identityOver G.total
unit_preserved := fun _ => rfl
multiply_preserved := fun _ _ _ => rfl }
map_identity := fun _ _ => rfl
map_composition := fun _ _ _ => rfl
/-- The terminal object B→B, which is the domain of the identity section. -/
def baseOver (B : KSpace) : SpaceOver B := ⟨B, ContinuousMap.id B⟩
/-- The canonical identity section as a map over B (PDF pp. 5--6). -/
def groupUnitSection {B : KSpace} (G : ParametrizedGroup B) :
MapOver (baseOver B) G.total where
map := G.unit
over_base := G.unit_over
/-- Well-sectionedness is the strong cofibration property of the canonical
identity section, not an arbitrary supplied section (Definition 6, PDF p. 6). -/
def IsWellSectioned {B : KSpace} (G : ParametrizedGroup B) : Prop :=
IsStrongFCofibration (groupUnitSection G)
/-- Goodness requires every degeneracy in every degree to be a strong
fbar-cofibration (Definition 20, PDF p. 12). -/
def IsGoodSimplicialGroup {B : KSpace} (G : SimplicialParametrizedGroup B) : Prop :=
∀ (n : ℕ) (i : Fin (n + 1)),
IsStrongFCofibration ((G.map (SimplexCategory.σ i).op).map)
/-- Sanity: every degeneracy of the constant simplicial group is exactly
the identity on the given group, including degree zero. -/
example {B : KSpace} (G : ParametrizedGroup B) (n : ℕ) (i : Fin (n + 1))
(x : G.total.space) :
(((constantSimplicialGroup G).map (SimplexCategory.σ i).op).map.map x) = x := by
rfl
end QAlgorithms.Papers.Independent.Intakethird100.P73
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What the Lean code literally says, in plain math · gpt-6.1-sol
QAlgorithms.Papers.Independent.Intakethird100.P73.EquivariantCylinderMap
Let be a compactly generated topological space, a parametrized group over , and right -spaces over . Explicitly, the total spaces are compactly generated; their projections are continuous; has a continuous unit section and inverse and fiberwise group multiplication; and have projection-preserving right actions satisfying the unit and associativity laws. Multiplication and actions are continuous on the kifications of their same-fiber pair spaces. For any space , write for its underlying set with the topology in which is open exactly when every continuous map from a compact Hausdorff space into has open inverse image of . An equivariant cylinder map from to consists of a continuous function
such that, for every and , , and, for every with ,
No endpoint values are prescribed. Empty spaces and empty fibers are permitted.
QAlgorithms.Papers.Independent.Intakethird100.P73.EquivariantMap
Let be a compactly generated topological space, and let be a parametrized group over : its compactly generated total space has a projection , a continuous unit section, a continuous inverse preserving the projection, and multiplication on pairs in the same fiber, continuous on the kification of that fiber product, satisfying the group laws in every fiber. Here kification keeps the underlying set and declares a subset open exactly when its inverse image under every continuous map from a compact Hausdorff space into the original space is open. Let and be compactly generated spaces with continuous projections to and right -actions preserving these projections, continuous on the kified fiber products, and satisfying the unit and action associativity laws. An equivariant map from to consists of a continuous function such that for every , together with the requirement
The spaces and their fibers need not be nonempty; conditions quantified over empty domains are vacuous.
QAlgorithms.Papers.Independent.Intakethird100.P73.EquivariantSpace
For any compactly generated topological space , fix a parametrized group consisting of a compactly generated space with continuous projection , a continuous section , a continuous multiplication preserving the common projection, and a continuous inverse map preserving projection, with , for every , and whenever ; here for every . For this fixed , the structure consists of a compactly generated topological space with a continuous projection and a continuous action satisfying for every pair with , together with the identities
for every , and
for every and with and . In this description, and , initially with their ordinary product subspace topologies; for either such space , has the same underlying set with open exactly when is open for every compact Hausdorff space in the fixed universe and every originally continuous map . Each multiplication or action is evaluated on a pair together with the required equality of projections. The space may be empty, in which case its action identities are vacuous.
QAlgorithms.Papers.Independent.Intakethird100.P73.EquivariantlyHomotopic
Let be a compactly generated topological space, a parametrized group over , and compactly generated right -spaces over . This means that has continuous projection, unit section and inverse and fiberwise group laws, while have continuous projections and projection-preserving, unital, associative right actions; multiplication and actions are continuous on their kified fiber products. Write for the same set as , with a subset open exactly when its inverse image under every continuous compact Hausdorff probe into is open. For any continuous projection-preserving, action-preserving maps , the assertion that they are equivariantly homotopic means that there exists a continuous
such that, for every and ,
and for every with . No nonemptiness is assumed; if is empty, all the pointwise conditions are vacuous and the empty function supplies such a homotopy.
QAlgorithms.Papers.Independent.Intakethird100.P73.FiberProductSet
For any compactly generated topological space and any compactly generated topological spaces equipped with continuous projections and , this abbreviation denotes the subtype
An element consists of a pair together with evidence that its two coordinates have equal projections. This subtype may be empty.
QAlgorithms.Papers.Independent.Intakethird100.P73.FiberwiseHomotopic
For any compactly generated topological space , compactly generated topological spaces with continuous projections , , and continuous maps satisfying , this predicate means that there exists a continuous map , where has its usual topology and has the same underlying set as the ordinary product, with a subset open exactly when is open for every compact Hausdorff space in the fixed universe and every continuous map for the ordinary product topology, such that
for every and every . There is no nonemptiness assumption on ; if is empty, the conditions are satisfied by the empty map.
QAlgorithms.Papers.Independent.Intakethird100.P73.GroupMapOver
Let be a compactly generated topological space and let be parametrized groups over . Thus their compactly generated total spaces have continuous projections , continuous unit sections satisfying , continuous inverses preserving the projections, and multiplications defined on same-fiber pairs and satisfying the group laws in every fiber. These multiplications are continuous on the kifications of the fiber products, where kification declares a subset open exactly when its inverse image under every continuous map from a compact Hausdorff space into the original space is open. A group map over from to consists of a continuous such that, for every , , and such that
Preservation of inverses is not a separate field of the structure. The base may be empty; if it is nonempty, each group fiber contains its specified unit.
QAlgorithms.Papers.Independent.Intakethird100.P73.IsEquivariantFEquivalence
Let be a compactly generated topological space and a parametrized group over : its compactly generated total space has continuous projection, unit section and inverse, with group multiplication in each fiber continuous on the kified fiber product. Let be compactly generated spaces over carrying projection-preserving right -actions, continuous on the kified fiber products and satisfying the unit and associativity laws. For a space , let have the same underlying set, with subsets open precisely when all continuous maps from compact Hausdorff spaces into have open inverse images. A continuous projection-preserving, action-preserving map is an equivariant -equivalence exactly when there exist a continuous projection-preserving, action-preserving map and continuous maps
with
For all points and all , these maps preserve the base point and satisfy and whenever the indicated point and group element lie over the same base point. Neither uniqueness nor nonemptiness is required.
QAlgorithms.Papers.Independent.Intakethird100.P73.IsEquivariantFFibration
Let be a compactly generated topological space, a parametrized group over , and a continuous projection-preserving, action-preserving map between compactly generated right -spaces over . Here the group has continuous projection, unit section and inverse and fiberwise group laws, the actions preserve projections and satisfy the unit and associativity laws, and multiplication and actions are continuous on the kified same-fiber pair spaces. Write for the topology on the underlying set of whose open subsets are those having open inverse image under every continuous compact Hausdorff probe into . The assertion that is an equivariant -fibration means the following: for every such right -space , every continuous projection-preserving, action-preserving map , and every continuous map satisfying
where the action identity is required for all over the same base point and all , there exists a continuous satisfying, for all ,
and for all compatible . Empty test spaces are included; the lift is not required to be unique.
QAlgorithms.Papers.Independent.Intakethird100.P73.IsEquivariantFiberwiseNDR
Let be a compactly generated topological space, a parametrized group over , a compactly generated right -space over , and any subset of . Explicitly, has continuous projection, unit section and inverse and fiberwise group multiplication, while has a continuous projection and a projection-preserving, unital, associative right action; multiplication and action are continuous on the kified fiber products. Let denote the same set as , with subsets open exactly when their inverse images under every continuous compact Hausdorff probe into are open. The assertion that satisfy the equivariant fiberwise NDR condition means that there exist a continuous function and a continuous map such that for all , and for every compatible and every , with
and for every over the same base point. The endpoint inclusion is required only where . The subset is not separately assumed closed or invariant, and empty and empty are allowed.
QAlgorithms.Papers.Independent.Intakethird100.P73.IsEquivariantStrongFCofibration
Let be a compactly generated topological space, a parametrized group over , and a continuous projection-preserving, action-preserving map of compactly generated right -spaces over . The group has continuous projection, unit section and inverse and fiberwise group laws; the right actions preserve projections and satisfy the unit and associativity laws; multiplication and actions are continuous on kified fiber products. Write for the same set as , with open exactly when every continuous compact Hausdorff probe into has open inverse image of . In this paragraph an equivariant map means a continuous map preserving the projection and satisfying for compatible pairs; an equivariant homotopy from to means a continuous preserving the projection and the action at every time, with and . The assertion that is an equivariant strong -cofibration means that for every pair of these right -spaces and every equivariant having both of the following properties—every equivariant and equivariant homotopy with , for every right -space , admit an equivariant homotopy with and ; and there exists an equivariant with equivariant homotopies from to and from to —every pair of equivariant maps , satisfying for all admits an equivariant map such that
Neither injectivity of nor uniqueness of is part of this definition, and empty spaces are included.
QAlgorithms.Papers.Independent.Intakethird100.P73.IsFEquivalence
For any compactly generated topological space , compactly generated topological spaces with continuous projections , , and continuous map satisfying , this predicate means that there exist a continuous map satisfying and continuous maps and , where , such that
for all , , and . Here, for either ordinary product or , has the same set as , with open exactly when is open for every compact Hausdorff space in the fixed universe and every continuous map . The inverse and homotopies are required to exist but are not required to be unique; empty spaces are included in the quantification.
QAlgorithms.Papers.Independent.Intakethird100.P73.IsFFibration
For any compactly generated topological space , compactly generated topological spaces with continuous projections , , and continuous map satisfying , this predicate states the following lifting property. For every compactly generated topological space with continuous projection , every continuous map satisfying , and every continuous map , where , if
then there exists a continuous map such that
for every and . Here has the ordinary product’s underlying set, with open exactly when is open for every compact Hausdorff space in the fixed universe and every continuous map for the ordinary product topology. The quantification includes empty , for which the lifting conditions hold for the empty map.
QAlgorithms.Papers.Independent.Intakethird100.P73.IsGoodSimplicialGroup
For a compactly generated space and a simplicial parametrized group over , this defines a property of every degeneracy map , for every integer and every . Here assigns a parametrized group to each object of the opposite simplex category and a continuous map over preserving units and multiplication to each morphism, preserving identities and composition pointwise; each degree has a compactly generated total space , a continuous unit section, continuous inversion over , and continuous multiplication on the compactly generated replacement of the pairs in the same fiber, satisfying the group laws in each fiber. The map is assigned to the opposite of the order-preserving surjection that identifies and . Write , and let retain the underlying set of with the finest topology making every originally continuous map from a compact Hausdorff space in the same universe continuous. A map over is continuous and commutes with projections, and a homotopy over from to is a continuous with endpoints and . The required property is that, for every , every pair of compactly generated spaces over , and every map over satisfying the following two conditions, every commuting square with left side has a lift. The first condition on is that, for every compactly generated space over , map over , and continuous with and , there is a continuous with , , and for all . The second condition is that some map over admits homotopies over from to and from to . Explicitly, every pair of maps and over with for every must admit a map over with for every and for every . The quantifiers include , where , and impose no nonemptiness assumptions.
QAlgorithms.Papers.Independent.Intakethird100.P73.IsStrongFCofibration
For any compactly generated topological space , compactly generated topological spaces with continuous projections , , and continuous map satisfying , this predicate states that the following holds for every pair of compactly generated topological spaces with continuous projections , , and every continuous map satisfying . Suppose, first, that for every compactly generated space with continuous projection , every continuous with , and every continuous satisfying and , there exists a continuous satisfying , , and , for all . Suppose, second, that there exist a continuous with and continuous maps , satisfying , , , , , and , for all . Under these two suppositions, for every continuous and satisfying , , and for all , there exists a continuous satisfying
for all . Throughout, , and denotes the ordinary product’s underlying set with open exactly when is open for every compact Hausdorff space in the fixed universe and every ordinarily continuous . All quantified spaces may be empty, and the requirement on a particular is conditional on both suppositions holding.
QAlgorithms.Papers.Independent.Intakethird100.P73.IsWeaklyHausdorff
For a KSpace , meaning a type in universe equipped with a compactly generated topology, this defines the property that, for every compact Hausdorff space in universe and every continuous map , the image is closed in . Empty compact Hausdorff domains are included, in which case the image is empty; the property also permits itself to be empty.
QAlgorithms.Papers.Independent.Intakethird100.P73.IsWellSectioned
For a compactly generated space and a parametrized group over , with compactly generated total space , continuous projection , continuous unit section , continuous fiberwise inversion, and continuous fiberwise multiplication satisfying the group laws, this defines the following property of . Write , and write for the underlying set of a topological space equipped with the finest topology making every originally continuous map from a compact Hausdorff space in the same universe continuous; in particular, the multiplication of is continuous on . A map over means a continuous map commuting with the specified projections to , and a homotopy over from to means a continuous such that , , and for all . The property is that, for every pair of compactly generated spaces over and every map over satisfying both of the following conditions, every commuting square with left side has a lift: first, for every compactly generated space over , every map over , and every continuous with and , there exists a continuous with , , and for all ; second, there exists a map over with homotopies over from to and from to . Explicitly, for every map over and every map over such that for every , there must exist a map over such that for every and for every . No nonemptiness assumptions are imposed.
QAlgorithms.Papers.Independent.Intakethird100.P73.KSpace
A KSpace consists of a type in universe , a topology on , and a proof that with that topology is compactly generated. The underlying type is allowed to be empty.
QAlgorithms.Papers.Independent.Intakethird100.P73.MapOver
For every base equipped with a compactly generated topology and every two spaces over it, consisting of compactly generated spaces with continuous projections and , a MapOver from the first to the second consists of a continuous map and a proof that for every . When is empty, this equality condition is vacuous.
QAlgorithms.Papers.Independent.Intakethird100.P73.ParametrizedGroup
For a compactly generated topological space , this structure consists of a compactly generated topological space with a continuous projection ; a continuous map satisfying for every ; a continuous multiplication , where , satisfying for every ; and a continuous map satisfying for every . Here initially carries the product subspace topology, and has the same underlying set, with open exactly when is open for every compact Hausdorff space in the fixed universe and every continuous map for that subspace topology. These data must satisfy
for every , and
for every with and . Each occurrence of is applied to the indicated pair together with the equality of its projections. The section supplies an element in every fiber over a point of ; the base itself is allowed to be empty.
QAlgorithms.Papers.Independent.Intakethird100.P73.SimplicialParametrizedGroup
For a compactly generated topological space , a simplicial parametrized group over consists of a parametrized group over for every object of the opposite simplex category, and a group map over , denoted , for every arrow in that category. The simplex category has the nonempty finite ordered sets , for all natural numbers , including , and order-preserving maps; taking its opposite reverses the arrows. Each has a compactly generated total space , continuous projection , continuous unit section and inverse, and fiberwise group multiplication continuous on the kified fiber product and satisfying the group laws. Here kification gives the original underlying set the topology whose open subsets have open inverse image under every continuous compact Hausdorff probe into the original space. Each is continuous, preserves the projection to , sends each fiber unit to the corresponding fiber unit, and preserves products of elements lying in the same fiber. The required identity and composition laws are the pointwise equalities
for every triple of objects , every , every , and every . The base is not required to be nonempty.
QAlgorithms.Papers.Independent.Intakethird100.P73.SpaceOver
For every base that is a type in universe equipped with a compactly generated topology, a SpaceOver consists of another type in universe equipped with a compactly generated topology and a continuous map . The total space may be empty; if is empty, the existence of forces to be empty.
QAlgorithms.Papers.Independent.Intakethird100.P73.baseOver
For every compactly generated space , this defines a space over whose total space is itself and whose continuous projection to is the identity . There is no nonemptiness assumption on .
QAlgorithms.Papers.Independent.Intakethird100.P73.composeOver
For any compactly generated topological space , let be compactly generated topological spaces with continuous projections , , and . Given continuous maps and satisfying for every and for every , this definition gives the continuous map over , whose value at is and whose projection satisfies .
QAlgorithms.Papers.Independent.Intakethird100.P73.constantSimplicialGroup
For any compactly generated space and parametrized group over , this defines a constant simplicial parametrized group. Here consists of a compactly generated total space , a continuous projection , a continuous unit section with , a continuous inverse over , and a multiplication over defined on the compactly generated replacement of , satisfying the unit, inverse, and associativity laws in each fiber. The compactly generated replacement retains the underlying set and uses the finest topology making every originally continuous map from a compact Hausdorff space in the same universe continuous. The constructed simplicial object assigns this same to every object of the opposite simplex category and assigns the identity map of , over and preserving units and multiplication, to every morphism. Its identity and composition laws hold pointwise because all these maps are identities.
QAlgorithms.Papers.Independent.Intakethird100.P73.equivariantCompose
Let be a compactly generated topological space and a parametrized group over , meaning a compactly generated total space with a continuous projection to , continuous unit section and inverse, and fiberwise group multiplication continuous on the kified fiber product. Let be compactly generated spaces over with projection-preserving right -actions satisfying the unit and associativity laws and continuous on the corresponding kified fiber products. Kification gives a space the topology in which a subset is open exactly when its inverse image under every continuous compact Hausdorff probe into the original space is open. For any continuous projection-preserving, action-preserving maps and , this defines their equivariant composite by
It preserves the projection, , and for every and with , it satisfies . No nonemptiness assumptions are imposed.
QAlgorithms.Papers.Independent.Intakethird100.P73.equivariantIdentity
For every compactly generated topological space , every parametrized group over , and every right -space over , this defines the equivariant identity map by . Explicitly, has a compactly generated total space over , a continuous unit section and inverse, and fiberwise group multiplication continuous on the kified fiber product; is compactly generated with a continuous projection and a projection-preserving right action satisfying the unit and associativity laws and continuous on the kified same-fiber pairs. Kification means that a subset is open precisely when every continuous map from a compact Hausdorff space into the original space has open inverse image of that subset. The defined map is continuous, satisfies , and preserves the action because
for every lying over the same point of . This definition also applies when or is empty.
QAlgorithms.Papers.Independent.Intakethird100.P73.fiberPair
For any compactly generated topological space , compactly generated topological spaces with continuous projections , , points , , and evidence that , this definition returns the element represented by , together with that evidence, in the space whose underlying set is . Its topology is the compactly generated refinement of the ordinary product subspace topology: is open exactly when is open for every compact Hausdorff space in the fixed universe and every map continuous for that subspace topology. Its projection to sends to .
QAlgorithms.Papers.Independent.Intakethird100.P73.fiberProductMap
For any compactly generated topological space , let be compactly generated topological spaces with continuous projections to , and let and be continuous maps satisfying and . Put and , initially with their product subspace topologies. For either such space , write for the same set with the topology in which is open exactly when is open for every compact Hausdorff space in the fixed universe and every originally continuous map . This definition gives the continuous map over
The projections of these spaces to are respectively and , and preservation of the projection is the equality .
QAlgorithms.Papers.Independent.Intakethird100.P73.fiberProductOver
For any compactly generated topological space and compactly generated topological spaces with continuous projections and , form , initially with the subspace topology inherited from the product. This definition gives a space over whose underlying set is , whose topology is its compactly generated refinement, and whose continuous projection sends to . Explicitly, a subset is open in this refined topology exactly when is open for every compact Hausdorff space in the fixed universe and every map continuous for the original subspace topology. The projection is the original first-coordinate projection composed with the continuous identity map from this refined space to the original . The construction also applies when is empty.
QAlgorithms.Papers.Independent.Intakethird100.P73.fiberProductSetMap
For any compactly generated topological space , let be compactly generated topological spaces with continuous projections to . Given continuous maps and satisfying for every and for every , this definition gives the continuous map
where both subtypes carry their ordinary product subspace topologies. Membership of the output follows from .
QAlgorithms.Papers.Independent.Intakethird100.P73.groupUnitSection
For every compactly generated space and parametrized group over , this defines a continuous map over from , equipped with its identity projection, to the total space of . A parametrized group here has a continuous projection from a compactly generated total space, a continuous unit section , continuous inversion over , and continuous multiplication over on the compactly generated replacement of the space of pairs in the same fiber, with the group laws holding in each fiber. That replacement retains the underlying set and uses the finest topology making every originally continuous map from a compact Hausdorff space in the same universe continuous. The defined map is exactly ; the condition that it is over is the given equality for every .
QAlgorithms.Papers.Independent.Intakethird100.P73.identityOver
For every base equipped with a compactly generated topology and every space over it, consisting of a compactly generated space and a continuous projection , this defines a map from that space over to itself whose underlying continuous function is . Its required compatibility with the projection is for every ; the construction also applies when is empty.
QAlgorithms.Papers.Independent.Intakethird100.P73.kSpaceCoeSort
This instance allows any KSpace—a type in universe equipped with a compactly generated topology—to be used as a type, in which case it denotes its underlying carrier type.
QAlgorithms.Papers.Independent.Intakethird100.P73.kSpaceCompactlyGenerated
For every KSpace , consisting of a carrier type equipped with a topology and a proof of compact generation, this instance supplies the fact that the underlying type with its stored topology is compactly generated, using the proof stored in .
QAlgorithms.Papers.Independent.Intakethird100.P73.kSpaceTopology
For every KSpace , consisting of a carrier type, a topology, and a proof that this topology is compactly generated, this instance equips the underlying type of with exactly the topology stored in .
QAlgorithms.Papers.Independent.Intakethird100.P73.kify
For every type in universe equipped with a topology, this defines a KSpace with underlying type and the following topology: a subset is open precisely when is open for every compact Hausdorff space in universe and every map continuous for the original topology on . Equivalently, this is the final topology of the evaluation map from the disjoint union of all such domains indexed by pairs , sending the point indexed by to . The construction includes a proof that this topology is compactly generated and applies also when is empty.
QAlgorithms.Papers.Independent.Intakethird100.P73.kifyMap
For every pair of types in universe , each equipped with a topology, and every continuous map , this defines a continuous map with underlying function after replacing both topologies as follows: for either space , a subset is open in the replacement topology exactly when is open for every compact Hausdorff space in universe and every map continuous for the original topology. The construction includes empty spaces whenever the supplied map exists.
QAlgorithms.Papers.Independent.Intakethird100.P73.kifyProbe
For every type in universe equipped with a topology, every compact Hausdorff space in universe , and every continuous map , this defines a continuous map with the same underlying function from to the underlying set equipped with the topology in which is open exactly when is open for every compact Hausdorff space in universe and every originally continuous map . Empty domains are included; if is empty, the given function can exist only when is empty.
QAlgorithms.Papers.Independent.Intakethird100.P73.kifyProjection
For every type in universe equipped with a topology , this defines a continuous map whose underlying function is the identity on , from equipped with the topology in which is open exactly when is open for every compact Hausdorff space in universe and every -continuous map , to equipped with its original topology . No nonemptiness assumption on is imposed.
Confirmed by the mission captain (proposal self-audit).
Confirmed by the moderator at approval.