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coe_comap (f : C(α, β)) (U : opens β) : ↑(comap f U) = f ⁻¹' U
rfl
lemma
topological_space.opens.coe_comap
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_comp (g : C(β, γ)) (f : C(α, β)) : comap (g.comp f) = (comap f).comp (comap g)
rfl
lemma
topological_space.opens.comap_comp
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_comap (g : C(β, γ)) (f : C(α, β)) (U : opens γ) : comap f (comap g U) = comap (g.comp f) U
rfl
lemma
topological_space.opens.comap_comap
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_injective [t0_space β] : injective (comap : C(α, β) → frame_hom (opens β) (opens α))
λ f g h, continuous_map.ext $ λ a, inseparable.eq $ inseparable_iff_forall_open.2 $ λ s hs, have comap f ⟨s, hs⟩ = comap g ⟨s, hs⟩, from fun_like.congr_fun h ⟨_, hs⟩, show a ∈ f ⁻¹' s ↔ a ∈ g ⁻¹' s, from set.ext_iff.1 (coe_inj.2 this) a
lemma
topological_space.opens.comap_injective
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[ "continuous_map.ext", "frame_hom", "fun_like.congr_fun", "inseparable.eq", "t0_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.homeomorph.opens_congr (f : α ≃ₜ β) : opens α ≃o opens β
{ to_fun := opens.comap f.symm.to_continuous_map, inv_fun := opens.comap f.to_continuous_map, left_inv := by { intro U, ext1, exact f.to_equiv.preimage_symm_preimage _ }, right_inv := by { intro U, ext1, exact f.to_equiv.symm_preimage_preimage _ }, map_rel_iff' := λ U V, by simp only [← set_like.coe_subset_coe]...
def
homeomorph.opens_congr
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[ "inv_fun", "set_like.coe_subset_coe" ]
A homeomorphism induces an order-preserving equivalence on open sets, by taking comaps.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.homeomorph.opens_congr_symm (f : α ≃ₜ β) : f.opens_congr.symm = f.symm.opens_congr
rfl
lemma
homeomorph.opens_congr_symm
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
open_nhds_of (x : α) extends opens α
(mem' : x ∈ carrier)
structure
topological_space.open_nhds_of
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[]
The open neighborhoods of a point. See also `opens` or `nhds`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_opens_injective : injective (to_opens : open_nhds_of x → opens α)
| ⟨_, _⟩ ⟨_, _⟩ rfl := rfl
lemma
topological_space.open_nhds_of.to_opens_injective
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
can_lift_set : can_lift (set α) (open_nhds_of x) coe (λ s, is_open s ∧ x ∈ s)
⟨λ s hs, ⟨⟨⟨s, hs.1⟩, hs.2⟩, rfl⟩⟩
instance
topological_space.open_nhds_of.can_lift_set
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[ "can_lift", "is_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem (U : open_nhds_of x) : x ∈ U
U.mem'
lemma
topological_space.open_nhds_of.mem
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open (U : open_nhds_of x) : is_open (U : set α)
U.is_open'
lemma
topological_space.open_nhds_of.is_open
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[ "is_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
basis_nhds : (𝓝 x).has_basis (λ U : open_nhds_of x, true) coe
(nhds_basis_opens x).to_has_basis (λ U hU, ⟨⟨⟨U, hU.2⟩, hU.1⟩, trivial, subset.rfl⟩) (λ U _, ⟨U, ⟨⟨U.mem, U.is_open⟩, subset.rfl⟩⟩)
lemma
topological_space.open_nhds_of.basis_nhds
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[ "nhds_basis_opens" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap (f : C(α, β)) (x : α) : lattice_hom (open_nhds_of (f x)) (open_nhds_of x)
{ to_fun := λ U, ⟨opens.comap f U.1, U.mem⟩, map_sup' := λ U V, rfl, map_inf' := λ U V, rfl }
def
topological_space.open_nhds_of.comap
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[ "lattice_hom" ]
Preimage of an open neighborhood of `f x` under a continuous map `f` as a `lattice_hom`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
opens_find_tac : expr → option auto_cases_tac
| `(topological_space.opens _) := tac_cases | _ := none
def
tactic.auto_cases.opens_find_tac
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[]
Find an `auto_cases_tac` which matches `topological_space.opens`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
auto_cases_opens : tactic string
auto_cases tactic.auto_cases.opens_find_tac
def
tactic.auto_cases_opens
topology.sets
src/topology/sets/opens.lean
[ "order.hom.complete_lattice", "topology.bases", "topology.homeomorph", "topology.continuous_function.basic", "order.compactly_generated", "tactic.auto_cases" ]
[ "tactic.auto_cases.opens_find_tac" ]
A version of `tactic.auto_cases` that works for `topological_space.opens`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
clopen_upper_set (α : Type*) [topological_space α] [has_le α] extends clopens α
(upper' : is_upper_set carrier)
structure
clopen_upper_set
topology.sets
src/topology/sets/order.lean
[ "order.upper_lower.basic", "topology.sets.closeds" ]
[ "is_upper_set", "topological_space" ]
The type of clopen upper sets of a topological space.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
upper (s : clopen_upper_set α) : is_upper_set (s : set α)
s.upper'
lemma
clopen_upper_set.upper
topology.sets
src/topology/sets/order.lean
[ "order.upper_lower.basic", "topology.sets.closeds" ]
[ "clopen_upper_set", "is_upper_set" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
clopen (s : clopen_upper_set α) : is_clopen (s : set α)
s.clopen'
lemma
clopen_upper_set.clopen
topology.sets
src/topology/sets/order.lean
[ "order.upper_lower.basic", "topology.sets.closeds" ]
[ "clopen_upper_set", "is_clopen" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_upper_set (s : clopen_upper_set α) : upper_set α
⟨s, s.upper⟩
def
clopen_upper_set.to_upper_set
topology.sets
src/topology/sets/order.lean
[ "order.upper_lower.basic", "topology.sets.closeds" ]
[ "clopen_upper_set", "upper_set" ]
Reinterpret a upper clopen as an upper set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ext {s t : clopen_upper_set α} (h : (s : set α) = t) : s = t
set_like.ext' h
lemma
clopen_upper_set.ext
topology.sets
src/topology/sets/order.lean
[ "order.upper_lower.basic", "topology.sets.closeds" ]
[ "clopen_upper_set", "set_like.ext'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_mk (s : clopens α) (h) : (mk s h : set α) = s
rfl
lemma
clopen_upper_set.coe_mk
topology.sets
src/topology/sets/order.lean
[ "order.upper_lower.basic", "topology.sets.closeds" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_sup (s t : clopen_upper_set α) : (↑(s ⊔ t) : set α) = s ∪ t
rfl
lemma
clopen_upper_set.coe_sup
topology.sets
src/topology/sets/order.lean
[ "order.upper_lower.basic", "topology.sets.closeds" ]
[ "clopen_upper_set" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_inf (s t : clopen_upper_set α) : (↑(s ⊓ t) : set α) = s ∩ t
rfl
lemma
clopen_upper_set.coe_inf
topology.sets
src/topology/sets/order.lean
[ "order.upper_lower.basic", "topology.sets.closeds" ]
[ "clopen_upper_set" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_top : (↑(⊤ : clopen_upper_set α) : set α) = univ
rfl
lemma
clopen_upper_set.coe_top
topology.sets
src/topology/sets/order.lean
[ "order.upper_lower.basic", "topology.sets.closeds" ]
[ "clopen_upper_set" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_bot : (↑(⊥ : clopen_upper_set α) : set α) = ∅
rfl
lemma
clopen_upper_set.coe_bot
topology.sets
src/topology/sets/order.lean
[ "order.upper_lower.basic", "topology.sets.closeds" ]
[ "clopen_upper_set" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Sheaf_is_abelian [has_finite_limits D] : abelian (Sheaf J D)
let adj := sheafification_adjunction J D in abelian_of_adjunction _ _ (as_iso adj.counit) adj
instance
category_theory.Sheaf_is_abelian
topology.sheaves
src/topology/sheaves/abelian.lean
[ "category_theory.abelian.functor_category", "category_theory.preadditive.additive_functor", "category_theory.preadditive.functor_category", "category_theory.abelian.transfer", "category_theory.sites.left_exact" ]
[ "adj" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
presheaf_to_Sheaf_additive : (presheaf_to_Sheaf J D).additive
(presheaf_to_Sheaf J D).additive_of_preserves_binary_biproducts
instance
category_theory.presheaf_to_Sheaf_additive
topology.sheaves
src/topology/sheaves/abelian.lean
[ "category_theory.abelian.functor_category", "category_theory.preadditive.additive_functor", "category_theory.preadditive.functor_category", "category_theory.abelian.transfer", "category_theory.sites.left_exact" ]
[ "additive" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diagram_comp_preserves_limits : diagram F U ⋙ G ≅ diagram.{v} (F ⋙ G) U
begin fapply nat_iso.of_components, rintro ⟨j⟩, exact (preserves_product.iso _ _), exact (preserves_product.iso _ _), rintros ⟨⟩ ⟨⟩ ⟨⟩, { ext, simp, dsimp, simp, }, -- non-terminal `simp`, but `squeeze_simp` fails { ext, simp only [limit.lift_π, functor.comp_map, map_lift_pi_comparison, fan.mk_π_app, ...
def
Top.presheaf.sheaf_condition.diagram_comp_preserves_limits
topology.sheaves
src/topology/sheaves/forget.lean
[ "category_theory.limits.preserves.shapes.products", "topology.sheaves.sheaf_condition.equalizer_products" ]
[]
When `G` preserves limits, the sheaf condition diagram for `F` composed with `G` is naturally isomorphic to the sheaf condition diagram for `F ⋙ G`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_cone_fork : G.map_cone (fork.{v} F U) ≅ (cones.postcompose (diagram_comp_preserves_limits G F U).inv).obj (fork (F ⋙ G) U)
cones.ext (iso.refl _) (λ j, begin dsimp, simp [diagram_comp_preserves_limits], cases j; dsimp, { rw iso.eq_comp_inv, ext, simp, dsimp, simp, }, { rw iso.eq_comp_inv, ext, simp, -- non-terminal `simp`, but `squeeze_simp` fails dsimp, simp only [limit.lift_π, fan.mk_π_app, ←G.map_comp, limi...
def
Top.presheaf.sheaf_condition.map_cone_fork
topology.sheaves
src/topology/sheaves/forget.lean
[ "category_theory.limits.preserves.shapes.products", "topology.sheaves.sheaf_condition.equalizer_products" ]
[]
When `G` preserves limits, the image under `G` of the sheaf condition fork for `F` is the sheaf condition fork for `F ⋙ G`, postcomposed with the inverse of the natural isomorphism `diagram_comp_preserves_limits`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_sheaf_iff_is_sheaf_comp : presheaf.is_sheaf F ↔ presheaf.is_sheaf (F ⋙ G)
begin rw [presheaf.is_sheaf_iff_is_sheaf_equalizer_products, presheaf.is_sheaf_iff_is_sheaf_equalizer_products], split, { intros S ι U, -- We have that the sheaf condition fork for `F` is a limit fork, obtain ⟨t₁⟩ := S U, -- and since `G` preserves limits, the image under `G` of this fork is a lim...
lemma
Top.presheaf.is_sheaf_iff_is_sheaf_comp
topology.sheaves
src/topology/sheaves/forget.lean
[ "category_theory.limits.preserves.shapes.products", "topology.sheaves.sheaf_condition.equalizer_products" ]
[]
If `G : C ⥤ D` is a functor which reflects isomorphisms and preserves limits (we assume all limits exist in both `C` and `D`), then checking the sheaf condition for a presheaf `F : presheaf C X` is equivalent to checking the sheaf condition for `F ⋙ G`. The important special case is when `C` is a concrete category wit...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_diagram : pairwise.diagram U ⋙ opens.map f = pairwise.diagram ((opens.map f).obj ∘ U)
begin apply functor.hext, abstract obj_eq {intro i, cases i; refl}, intros i j g, apply subsingleton.helim, iterate 2 {rw map_diagram.obj_eq}, end
lemma
Top.presheaf.sheaf_condition_pairwise_intersections.map_diagram
topology.sheaves
src/topology/sheaves/functors.lean
[ "topology.sheaves.sheaf_condition.pairwise_intersections" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_cocone : (opens.map f).map_cocone (pairwise.cocone U) == pairwise.cocone ((opens.map f).obj ∘ U)
begin unfold functor.map_cocone cocones.functoriality, dsimp, congr, iterate 2 {rw map_diagram, rw opens.map_supr}, apply subsingleton.helim, rw [map_diagram, opens.map_supr], apply proof_irrel_heq, end
lemma
Top.presheaf.sheaf_condition_pairwise_intersections.map_cocone
topology.sheaves
src/topology/sheaves/functors.lean
[ "topology.sheaves.sheaf_condition.pairwise_intersections" ]
[ "proof_irrel_heq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward_sheaf_of_sheaf {F : presheaf C X} (h : F.is_sheaf_pairwise_intersections) : (f _* F).is_sheaf_pairwise_intersections
λ ι U, begin convert h ((opens.map f).obj ∘ U) using 2, rw ← map_diagram, refl, change F.map_cone ((opens.map f).map_cocone _).op == _, congr, iterate 2 {rw map_diagram}, apply map_cocone, end
theorem
Top.presheaf.sheaf_condition_pairwise_intersections.pushforward_sheaf_of_sheaf
topology.sheaves
src/topology/sheaves/functors.lean
[ "topology.sheaves.sheaf_condition.pairwise_intersections" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward_sheaf_of_sheaf {F : X.presheaf C} (h : F.is_sheaf) : (f _* F).is_sheaf
by rw is_sheaf_iff_is_sheaf_pairwise_intersections at h ⊢; exact sheaf_condition_pairwise_intersections.pushforward_sheaf_of_sheaf f h
theorem
Top.sheaf.pushforward_sheaf_of_sheaf
topology.sheaves
src/topology/sheaves/functors.lean
[ "topology.sheaves.sheaf_condition.pairwise_intersections" ]
[]
The pushforward of a sheaf (by a continuous map) is a sheaf.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward (f : X ⟶ Y) : X.sheaf C ⥤ Y.sheaf C
{ obj := λ ℱ, ⟨f _* ℱ.1, pushforward_sheaf_of_sheaf f ℱ.2⟩, map := λ _ _ g, ⟨pushforward_map f g.1⟩ }
def
Top.sheaf.pushforward
topology.sheaves
src/topology/sheaves/functors.lean
[ "topology.sheaves.sheaf_condition.pairwise_intersections" ]
[]
The pushforward functor.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_sheaf_of_is_limit [has_limits C] {X : Top} (F : J ⥤ presheaf.{v} C X) (H : ∀ j, (F.obj j).is_sheaf) {c : cone F} (hc : is_limit c) : c.X.is_sheaf
begin let F' : J ⥤ sheaf C X := { obj := λ j, ⟨F.obj j, H j⟩, map := λ X Y f, ⟨F.map f⟩ }, let e : F' ⋙ sheaf.forget C X ≅ F := nat_iso.of_components (λ _, iso.refl _) (by tidy), exact presheaf.is_sheaf_of_iso ((is_limit_of_preserves (sheaf.forget C X) (limit.is_limit F')).cone_points_iso_of_nat_iso hc e) (...
lemma
Top.is_sheaf_of_is_limit
topology.sheaves
src/topology/sheaves/limits.lean
[ "topology.sheaves.sheaf", "category_theory.sites.limits", "category_theory.limits.functor_category" ]
[ "Top" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
limit_is_sheaf [has_limits C] {X : Top} (F : J ⥤ presheaf.{v} C X) (H : ∀ j, (F.obj j).is_sheaf) : (limit F).is_sheaf
is_sheaf_of_is_limit F H (limit.is_limit F)
lemma
Top.limit_is_sheaf
topology.sheaves
src/topology/sheaves/limits.lean
[ "topology.sheaves.sheaf", "category_theory.sites.limits", "category_theory.limits.functor_category" ]
[ "Top" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_locally_surjective (T : ℱ ⟶ 𝒢)
category_theory.is_locally_surjective (opens.grothendieck_topology X) T
def
Top.presheaf.is_locally_surjective
topology.sheaves
src/topology/sheaves/locally_surjective.lean
[ "topology.sheaves.presheaf", "topology.sheaves.stalks", "category_theory.sites.surjective" ]
[ "category_theory.is_locally_surjective", "opens.grothendieck_topology" ]
A map of presheaves `T : ℱ ⟶ 𝒢` is **locally surjective** if for any open set `U`, section `t` over `U`, and `x ∈ U`, there exists an open set `x ∈ V ⊆ U` and a section `s` over `V` such that `$T_*(s_V) = t|_V$`. See `is_locally_surjective_iff` below.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_locally_surjective_iff (T : ℱ ⟶ 𝒢) : is_locally_surjective T ↔ ∀ U t (x ∈ U), ∃ V (ι : V ⟶ U), (∃ s, T.app _ s = t |_ₕ ι) ∧ x ∈ V
iff.rfl
lemma
Top.presheaf.is_locally_surjective_iff
topology.sheaves
src/topology/sheaves/locally_surjective.lean
[ "topology.sheaves.presheaf", "topology.sheaves.stalks", "category_theory.sites.surjective" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
locally_surjective_iff_surjective_on_stalks (T : ℱ ⟶ 𝒢) : is_locally_surjective T ↔ ∀ (x : X), function.surjective ((stalk_functor C x).map T)
begin split; intro hT, { /- human proof: Let g ∈ Γₛₜ 𝒢 x be a germ. Represent it on an open set U ⊆ X as ⟨t, U⟩. By local surjectivity, pass to a smaller open set V on which there exists s ∈ Γ_ ℱ V mapping to t |_ V. Then the germ of s maps to g -/ -- Let g ∈ Γₛₜ 𝒢 x be a germ. intros x g...
lemma
Top.presheaf.locally_surjective_iff_surjective_on_stalks
topology.sheaves
src/topology/sheaves/locally_surjective.lean
[ "topology.sheaves.presheaf", "topology.sheaves.stalks", "category_theory.sites.surjective" ]
[]
An equivalent condition for a map of presheaves to be locally surjective is for all the induced maps on stalks to be surjective.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prelocal_predicate
(pred : Π {U : opens X}, (Π x : U, T x) → Prop) (res : ∀ {U V : opens X} (i : U ⟶ V) (f : Π x : V, T x) (h : pred f), pred (λ x : U, f (i x)))
structure
Top.prelocal_predicate
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
Given a topological space `X : Top` and a type family `T : X → Type`, a `P : prelocal_predicate T` consists of: * a family of predicates `P.pred`, one for each `U : opens X`, of the form `(Π x : U, T x) → Prop` * a proof that if `f : Π x : V, T x` satisfies the predicate on `V : opens X`, then the restriction of `f` ...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_prelocal (T : Top.{v}) : prelocal_predicate (λ x : X, T)
{ pred := λ U f, continuous f, res := λ U V i f h, continuous.comp h (opens.open_embedding_of_le i.le).continuous, }
def
Top.continuous_prelocal
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[ "continuous", "continuous.comp" ]
Continuity is a "prelocal" predicate on functions to a fixed topological space `T`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inhabited_prelocal_predicate (T : Top.{v}) : inhabited (prelocal_predicate (λ x : X, T))
⟨continuous_prelocal X T⟩
instance
Top.inhabited_prelocal_predicate
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
Satisfying the inhabited linter.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
local_predicate extends prelocal_predicate T
(locality : ∀ {U : opens X} (f : Π x : U, T x) (w : ∀ x : U, ∃ (V : opens X) (m : x.1 ∈ V) (i : V ⟶ U), pred (λ x : V, f (i x : U))), pred f)
structure
Top.local_predicate
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
Given a topological space `X : Top` and a type family `T : X → Type`, a `P : local_predicate T` consists of: * a family of predicates `P.pred`, one for each `U : opens X`, of the form `(Π x : U, T x) → Prop` * a proof that if `f : Π x : V, T x` satisfies the predicate on `V : opens X`, then the restriction of `f` to ...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_local (T : Top.{v}) : local_predicate (λ x : X, T)
{ locality := λ U f w, begin apply continuous_iff_continuous_at.2, intro x, specialize w x, rcases w with ⟨V, m, i, w⟩, dsimp at w, rw continuous_iff_continuous_at at w, specialize w ⟨x, m⟩, simpa using (opens.open_embedding_of_le i.le).continuous_at_iff.1 w, end, ..conti...
def
Top.continuous_local
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[ "continuous_iff_continuous_at" ]
Continuity is a "local" predicate on functions to a fixed topological space `T`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inhabited_local_predicate (T : Top.{v}) : inhabited (local_predicate _)
⟨continuous_local X T⟩
instance
Top.inhabited_local_predicate
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
Satisfying the inhabited linter.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prelocal_predicate.sheafify {T : X → Type v} (P : prelocal_predicate T) : local_predicate T
{ pred := λ U f, ∀ x : U, ∃ (V : opens X) (m : x.1 ∈ V) (i : V ⟶ U), P.pred (λ x : V, f (i x : U)), res := λ V U i f w x, begin specialize w (i x), rcases w with ⟨V', m', i', p⟩, refine ⟨V ⊓ V', ⟨x.2,m'⟩, opens.inf_le_left _ _, _⟩, convert P.res (opens.inf_le_right V V') _ p, end, locality := λ ...
def
Top.prelocal_predicate.sheafify
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
Given a `P : prelocal_predicate`, we can always construct a `local_predicate` by asking that the condition from `P` holds locally near every point.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prelocal_predicate.sheafify_of {T : X → Type v} {P : prelocal_predicate T} {U : opens X} {f : Π x : U, T x} (h : P.pred f) : P.sheafify.pred f
λ x, ⟨U, x.2, 𝟙 _, by { convert h, ext ⟨y, w⟩, refl, }⟩
lemma
Top.prelocal_predicate.sheafify_of
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subpresheaf_to_Types (P : prelocal_predicate T) : presheaf (Type v) X
{ obj := λ U, { f : Π x : unop U, T x // P.pred f }, map := λ U V i f, ⟨λ x, f.1 (i.unop x), P.res i.unop f.1 f.2⟩ }.
def
Top.subpresheaf_to_Types
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
The subpresheaf of dependent functions on `X` satisfying the "pre-local" predicate `P`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subtype : subpresheaf_to_Types P ⟶ presheaf_to_Types X T
{ app := λ U f, f.1 }
def
Top.subpresheaf_to_Types.subtype
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
The natural transformation including the subpresheaf of functions satisfying a local predicate into the presheaf of all functions.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_sheaf (P : local_predicate T) : (subpresheaf_to_Types P.to_prelocal_predicate).is_sheaf
presheaf.is_sheaf_of_is_sheaf_unique_gluing_types _ $ λ ι U sf sf_comp, begin -- We show the sheaf condition in terms of unique gluing. -- First we obtain a family of sections for the underlying sheaf of functions, -- by forgetting that the prediacte holds let sf' : Π i : ι, (presheaf_to_Types X T).obj (op (U i...
lemma
Top.subpresheaf_to_Types.is_sheaf
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
The functions satisfying a local predicate satisfy the sheaf condition.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subsheaf_to_Types (P : local_predicate T) : sheaf (Type v) X
⟨subpresheaf_to_Types P.to_prelocal_predicate, subpresheaf_to_Types.is_sheaf P⟩
def
Top.subsheaf_to_Types
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
The subsheaf of the sheaf of all dependently typed functions satisfying the local predicate `P`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
stalk_to_fiber (P : local_predicate T) (x : X) : (subsheaf_to_Types P).presheaf.stalk x ⟶ T x
begin refine colimit.desc _ { X := T x, ι := { app := λ U f, _, naturality' := _ } }, { exact f.1 ⟨x, (unop U).2⟩, }, { tidy, } end
def
Top.stalk_to_fiber
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
There is a canonical map from the stalk to the original fiber, given by evaluating sections.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
stalk_to_fiber_germ (P : local_predicate T) (U : opens X) (x : U) (f) : stalk_to_fiber P x ((subsheaf_to_Types P).presheaf.germ x f) = f.1 x
begin dsimp [presheaf.germ, stalk_to_fiber], cases x, simp, refl, end
lemma
Top.stalk_to_fiber_germ
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
stalk_to_fiber_surjective (P : local_predicate T) (x : X) (w : ∀ (t : T x), ∃ (U : open_nhds x) (f : Π y : U.1, T y) (h : P.pred f), f ⟨x, U.2⟩ = t) : function.surjective (stalk_to_fiber P x)
λ t, begin rcases w t with ⟨U, f, h, rfl⟩, fsplit, { exact (subsheaf_to_Types P).presheaf.germ ⟨x, U.2⟩ ⟨f, h⟩, }, { exact stalk_to_fiber_germ _ U.1 ⟨x, U.2⟩ ⟨f, h⟩, } end
lemma
Top.stalk_to_fiber_surjective
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
The `stalk_to_fiber` map is surjective at `x` if every point in the fiber `T x` has an allowed section passing through it.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
stalk_to_fiber_injective (P : local_predicate T) (x : X) (w : ∀ (U V : open_nhds x) (fU : Π y : U.1, T y) (hU : P.pred fU) (fV : Π y : V.1, T y) (hV : P.pred fV) (e : fU ⟨x, U.2⟩ = fV ⟨x, V.2⟩), ∃ (W : open_nhds x) (iU : W ⟶ U) (iV : W ⟶ V), ∀ (w : W.1), fU (iU w : U.1) = fV (iV w : V.1)) : function.injecti...
λ tU tV h, begin -- We promise to provide all the ingredients of the proof later: let Q : ∃ (W : (open_nhds x)ᵒᵖ) (s : Π w : (unop W).1, T w) (hW : P.pred s), tU = (subsheaf_to_Types P).presheaf.germ ⟨x, (unop W).2⟩ ⟨s, hW⟩ ∧ tV = (subsheaf_to_Types P).presheaf.germ ⟨x, (unop W).2⟩ ⟨s, hW⟩ := _, {...
lemma
Top.stalk_to_fiber_injective
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
The `stalk_to_fiber` map is injective at `x` if any two allowed sections which agree at `x` agree on some neighborhood of `x`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subpresheaf_continuous_prelocal_iso_presheaf_to_Top (T : Top.{v}) : subpresheaf_to_Types (continuous_prelocal X T) ≅ presheaf_to_Top X T
nat_iso.of_components (λ X, { hom := by { rintro ⟨f, c⟩, exact ⟨f, c⟩, }, inv := by { rintro ⟨f, c⟩, exact ⟨f, c⟩, }, hom_inv_id' := by { ext ⟨f, p⟩ x, refl, }, inv_hom_id' := by { ext ⟨f, p⟩ x, refl, }, }) (by tidy)
def
Top.subpresheaf_continuous_prelocal_iso_presheaf_to_Top
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
Some repackaging: the presheaf of functions satisfying `continuous_prelocal` is just the same thing as the presheaf of continuous functions.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sheaf_to_Top (T : Top.{v}) : sheaf (Type v) X
⟨presheaf_to_Top X T, presheaf.is_sheaf_of_iso (subpresheaf_continuous_prelocal_iso_presheaf_to_Top T) (subpresheaf_to_Types.is_sheaf (continuous_local X T))⟩
def
Top.sheaf_to_Top
topology.sheaves
src/topology/sheaves/local_predicate.lean
[ "topology.sheaves.sheaf_of_functions", "topology.sheaves.stalks", "topology.local_homeomorph", "topology.sheaves.sheaf_condition.unique_gluing" ]
[]
The sheaf of continuous functions on `X` with values in a space `T`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
submonoid_presheaf [∀ X : C, mul_one_class X] [∀ (X Y : C), monoid_hom_class (X ⟶ Y) X Y] (F : X.presheaf C)
(obj : ∀ U, submonoid (F.obj U)) (map : ∀ {U V : (opens X)ᵒᵖ} (i : U ⟶ V), (obj U) ≤ (obj V).comap (F.map i))
structure
Top.presheaf.submonoid_presheaf
topology.sheaves
src/topology/sheaves/operations.lean
[ "algebra.category.Ring.instances", "algebra.category.Ring.filtered_colimits", "ring_theory.localization.basic", "topology.sheaves.stalks" ]
[ "monoid_hom_class", "mul_one_class", "submonoid" ]
A subpresheaf with a submonoid structure on each of the components.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
submonoid_presheaf.localization_presheaf : X.presheaf CommRing
{ obj := λ U, CommRing.of $ localization (G.obj U), map := λ U V i, CommRing.of_hom $ is_localization.map _ (F.map i) (G.map i), map_id' := λ U, begin apply is_localization.ring_hom_ext (G.obj U), any_goals { dsimp, apply_instance }, refine (is_localization.map_comp _).trans _, rw F.map_id, refl...
def
Top.presheaf.submonoid_presheaf.localization_presheaf
topology.sheaves
src/topology/sheaves/operations.lean
[ "algebra.category.Ring.instances", "algebra.category.Ring.filtered_colimits", "ring_theory.localization.basic", "topology.sheaves.stalks" ]
[ "CommRing", "CommRing.of", "CommRing.of_hom", "is_localization.map", "is_localization.map_comp", "is_localization.map_comp_map", "is_localization.ring_hom_ext", "localization" ]
The localization of a presheaf of `CommRing`s with respect to a `submonoid_presheaf`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
submonoid_presheaf.to_localization_presheaf : F ⟶ G.localization_presheaf
{ app := λ U, CommRing.of_hom $ algebra_map (F.obj U) (localization $ G.obj U), naturality' := λ U V i, (is_localization.map_comp (G.map i)).symm }
def
Top.presheaf.submonoid_presheaf.to_localization_presheaf
topology.sheaves
src/topology/sheaves/operations.lean
[ "algebra.category.Ring.instances", "algebra.category.Ring.filtered_colimits", "ring_theory.localization.basic", "topology.sheaves.stalks" ]
[ "CommRing.of_hom", "algebra_map", "is_localization.map_comp", "localization" ]
The map into the localization presheaf.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
submonoid_presheaf_of_stalk (S : ∀ x : X, submonoid (F.stalk x)) : F.submonoid_presheaf
{ obj := λ U, ⨅ x : (unop U), submonoid.comap (F.germ x) (S x), map := λ U V i, begin intros s hs, simp only [submonoid.mem_comap, submonoid.mem_infi] at ⊢ hs, intro x, change (F.map i.unop.op ≫ F.germ x) s ∈ _, rw F.germ_res, exact hs _, end }
def
Top.presheaf.submonoid_presheaf_of_stalk
topology.sheaves
src/topology/sheaves/operations.lean
[ "algebra.category.Ring.instances", "algebra.category.Ring.filtered_colimits", "ring_theory.localization.basic", "topology.sheaves.stalks" ]
[ "submonoid", "submonoid.comap", "submonoid.mem_comap", "submonoid.mem_infi" ]
Given a submonoid at each of the stalks, we may define a submonoid presheaf consisting of sections whose restriction onto each stalk falls in the given submonoid.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
total_quotient_presheaf : X.presheaf CommRing.{w}
(F.submonoid_presheaf_of_stalk (λ x, (F.stalk x)⁰)).localization_presheaf
def
Top.presheaf.total_quotient_presheaf
topology.sheaves
src/topology/sheaves/operations.lean
[ "algebra.category.Ring.instances", "algebra.category.Ring.filtered_colimits", "ring_theory.localization.basic", "topology.sheaves.stalks" ]
[]
The localization of a presheaf of `CommRing`s at locally non-zero-divisor sections.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_total_quotient_presheaf : F ⟶ F.total_quotient_presheaf
submonoid_presheaf.to_localization_presheaf _
def
Top.presheaf.to_total_quotient_presheaf
topology.sheaves
src/topology/sheaves/operations.lean
[ "algebra.category.Ring.instances", "algebra.category.Ring.filtered_colimits", "ring_theory.localization.basic", "topology.sheaves.stalks" ]
[]
The map into the presheaf of total quotient rings
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
presheaf (X : Top.{w}) : Type (max u v w)
(opens X)ᵒᵖ ⥤ C
def
Top.presheaf
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
The category of `C`-valued presheaves on a (bundled) topological space `X`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_attr : user_attribute (tactic unit → tactic unit) unit
{ name := `sheaf_restrict, descr := "tag lemmas to use in `Top.presheaf.restrict_tac`", cache_cfg := { mk_cache := λ ns, pure $ λ t, do { ctx <- tactic.local_context, ctx.any_of (tactic.focus1 ∘ (tactic.apply' >=> (λ _, tactic.done)) >=> (λ _, t)) <|> ns.any_of (tactic.focus1 ∘ (tactic.re...
def
Top.presheaf.restrict_attr
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[ "tactic.apply'" ]
Tag lemmas to use in `Top.presheaf.restrict_tac`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_tac : Π (n : ℕ), tactic unit
| 0 := tactic.fail "`restrict_tac` failed" | (n + 1) := monad.join (restrict_attr.get_cache <*> pure tactic.done) <|> `[apply' le_trans, mjoin (restrict_attr.get_cache <*> pure (restrict_tac n))]
def
Top.presheaf.restrict_tac
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
A tactic to discharge goals of type `U ≤ V` for `Top.presheaf.restrict_open`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_tac'
restrict_tac 3
def
Top.presheaf.restrict_tac'
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
A tactic to discharge goals of type `U ≤ V` for `Top.presheaf.restrict_open`. Defaults to three iterations.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict {X : Top} {C : Type*} [category C] [concrete_category C] {F : X.presheaf C} {V : opens X} (x : F.obj (op V)) {U : opens X} (h : U ⟶ V) : F.obj (op U)
F.map h.op x
def
Top.presheaf.restrict
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[ "Top" ]
The restriction of a section along an inclusion of open sets. For `x : F.obj (op V)`, we provide the notation `x |_ₕ i` (`h` stands for `hom`) for `i : U ⟶ V`, and the notation `x |_ₗ U ⟪i⟫` (`l` stands for `le`) for `i : U ≤ V`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_open {X : Top} {C : Type*} [category C] [concrete_category C] {F : X.presheaf C} {V : opens X} (x : F.obj (op V)) (U : opens X) (e : U ≤ V . Top.presheaf.restrict_tac') : F.obj (op U)
x |_ₗ U ⟪e⟫
abbreviation
Top.presheaf.restrict_open
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[ "Top", "Top.presheaf.restrict_tac'" ]
The restriction of a section along an inclusion of open sets. For `x : F.obj (op V)`, we provide the notation `x |_ U`, where the proof `U ≤ V` is inferred by the tactic `Top.presheaf.restrict_tac'`
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_restrict {X : Top} {C : Type*} [category C] [concrete_category C] {F : X.presheaf C} {U V W : opens X} (e₁ : U ≤ V) (e₂ : V ≤ W) (x : F.obj (op W)) : x |_ V |_ U = x |_ U
by { delta restrict_open restrict, rw [← comp_apply, ← functor.map_comp], refl }
lemma
Top.presheaf.restrict_restrict
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[ "Top" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_restrict {X : Top} {C : Type*} [category C] [concrete_category C] {F G : X.presheaf C} (e : F ⟶ G) {U V : opens X} (h : U ≤ V) (x : F.obj (op V)) : e.app _ (x |_ U) = (e.app _ x) |_ U
by { delta restrict_open restrict, rw [← comp_apply, nat_trans.naturality, comp_apply] }
lemma
Top.presheaf.map_restrict
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[ "Top" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward_obj {X Y : Top.{w}} (f : X ⟶ Y) (ℱ : X.presheaf C) : Y.presheaf C
(opens.map f).op ⋙ ℱ
def
Top.presheaf.pushforward_obj
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
Pushforward a presheaf on `X` along a continuous map `f : X ⟶ Y`, obtaining a presheaf on `Y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward_obj_obj {X Y : Top.{w}} (f : X ⟶ Y) (ℱ : X.presheaf C) (U : (opens Y)ᵒᵖ) : (f _* ℱ).obj U = ℱ.obj ((opens.map f).op.obj U)
rfl
lemma
Top.presheaf.pushforward_obj_obj
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward_obj_map {X Y : Top.{w}} (f : X ⟶ Y) (ℱ : X.presheaf C) {U V : (opens Y)ᵒᵖ} (i : U ⟶ V) : (f _* ℱ).map i = ℱ.map ((opens.map f).op.map i)
rfl
lemma
Top.presheaf.pushforward_obj_map
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward_eq {X Y : Top.{w}} {f g : X ⟶ Y} (h : f = g) (ℱ : X.presheaf C) : f _* ℱ ≅ g _* ℱ
iso_whisker_right (nat_iso.op (opens.map_iso f g h).symm) ℱ
def
Top.presheaf.pushforward_eq
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
An equality of continuous maps induces a natural isomorphism between the pushforwards of a presheaf along those maps.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward_eq' {X Y : Top.{w}} {f g : X ⟶ Y} (h : f = g) (ℱ : X.presheaf C) : f _* ℱ = g _* ℱ
by rw h
lemma
Top.presheaf.pushforward_eq'
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward_eq_hom_app {X Y : Top.{w}} {f g : X ⟶ Y} (h : f = g) (ℱ : X.presheaf C) (U) : (pushforward_eq h ℱ).hom.app U = ℱ.map (begin dsimp [functor.op], apply quiver.hom.op, apply eq_to_hom, rw h, end)
by simp [pushforward_eq]
lemma
Top.presheaf.pushforward_eq_hom_app
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[ "quiver.hom.op" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward_eq'_hom_app {X Y : Top.{w}} {f g : X ⟶ Y} (h : f = g) (ℱ : X.presheaf C) (U) : nat_trans.app (eq_to_hom (pushforward_eq' h ℱ)) U = ℱ.map (eq_to_hom (by rw h))
by simpa [eq_to_hom_map]
lemma
Top.presheaf.pushforward_eq'_hom_app
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward_eq_rfl {X Y : Top.{w}} (f : X ⟶ Y) (ℱ : X.presheaf C) (U) : (pushforward_eq (rfl : f = f) ℱ).hom.app (op U) = 𝟙 _
begin dsimp [pushforward_eq], simp, end
lemma
Top.presheaf.pushforward_eq_rfl
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward_eq_eq {X Y : Top.{w}} {f g : X ⟶ Y} (h₁ h₂ : f = g) (ℱ : X.presheaf C) : ℱ.pushforward_eq h₁ = ℱ.pushforward_eq h₂
rfl
lemma
Top.presheaf.pushforward_eq_eq
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id : (𝟙 X) _* ℱ ≅ ℱ
(iso_whisker_right (nat_iso.op (opens.map_id X).symm) ℱ) ≪≫ functor.left_unitor _
def
Top.presheaf.pushforward.id
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
The natural isomorphism between the pushforward of a presheaf along the identity continuous map and the original presheaf.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id_eq : (𝟙 X) _* ℱ = ℱ
by { unfold pushforward_obj, rw opens.map_id_eq, erw functor.id_comp }
lemma
Top.presheaf.pushforward.id_eq
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id_hom_app' (U) (p) : (id ℱ).hom.app (op ⟨U, p⟩) = ℱ.map (𝟙 (op ⟨U, p⟩))
by { dsimp [id], simp, }
lemma
Top.presheaf.pushforward.id_hom_app'
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id_hom_app (U) : (id ℱ).hom.app U = ℱ.map (eq_to_hom (opens.op_map_id_obj U))
begin -- was `tidy` induction U using opposite.rec, cases U, rw [id_hom_app'], congr end
lemma
Top.presheaf.pushforward.id_hom_app
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[ "opposite.rec" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id_inv_app' (U) (p) : (id ℱ).inv.app (op ⟨U, p⟩) = ℱ.map (𝟙 (op ⟨U, p⟩))
by { dsimp [id], simp, }
lemma
Top.presheaf.pushforward.id_inv_app'
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp {Y Z : Top.{w}} (f : X ⟶ Y) (g : Y ⟶ Z) : (f ≫ g) _* ℱ ≅ g _* (f _* ℱ)
iso_whisker_right (nat_iso.op (opens.map_comp f g).symm) ℱ
def
Top.presheaf.pushforward.comp
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
The natural isomorphism between the pushforward of a presheaf along the composition of two continuous maps and the corresponding pushforward of a pushforward.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_eq {Y Z : Top.{w}} (f : X ⟶ Y) (g : Y ⟶ Z) : (f ≫ g) _* ℱ = g _* (f _* ℱ)
rfl
lemma
Top.presheaf.pushforward.comp_eq
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[ "comp_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_hom_app {Y Z : Top.{w}} (f : X ⟶ Y) (g : Y ⟶ Z) (U) : (comp ℱ f g).hom.app U = 𝟙 _
by { dsimp [comp], tidy, }
lemma
Top.presheaf.pushforward.comp_hom_app
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_inv_app {Y Z : Top.{w}} (f : X ⟶ Y) (g : Y ⟶ Z) (U) : (comp ℱ f g).inv.app U = 𝟙 _
by { dsimp [comp], tidy, }
lemma
Top.presheaf.pushforward.comp_inv_app
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward_map {X Y : Top.{w}} (f : X ⟶ Y) {ℱ 𝒢 : X.presheaf C} (α : ℱ ⟶ 𝒢) : f _* ℱ ⟶ f _* 𝒢
{ app := λ U, α.app _, naturality' := λ U V i, by { erw α.naturality, refl, } }
def
Top.presheaf.pushforward_map
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
A morphism of presheaves gives rise to a morphisms of the pushforwards of those presheaves.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pullback_obj {X Y : Top.{v}} (f : X ⟶ Y) (ℱ : Y.presheaf C) : X.presheaf C
(Lan (opens.map f).op).obj ℱ
def
Top.presheaf.pullback_obj
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
Pullback a presheaf on `Y` along a continuous map `f : X ⟶ Y`, obtaining a presheaf on `X`. This is defined in terms of left Kan extensions, which is just a fancy way of saying "take the colimits over the open sets whose preimage contains U".
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pullback_map {X Y : Top.{v}} (f : X ⟶ Y) {ℱ 𝒢 : Y.presheaf C} (α : ℱ ⟶ 𝒢) : pullback_obj f ℱ ⟶ pullback_obj f 𝒢
(Lan (opens.map f).op).map α
def
Top.presheaf.pullback_map
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
Pulling back along continuous maps is functorial.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pullback_obj_obj_of_image_open {X Y : Top.{v}} (f : X ⟶ Y) (ℱ : Y.presheaf C) (U : opens X) (H : is_open (f '' U)) : (pullback_obj f ℱ).obj (op U) ≅ ℱ.obj (op ⟨_, H⟩)
begin let x : costructured_arrow (opens.map f).op (op U) := begin refine @costructured_arrow.mk _ _ _ _ _ (op (opens.mk (f '' U) H)) _ _, exact ((@hom_of_le _ _ _ ((opens.map f).obj ⟨_, H⟩) (set.image_preimage.le_u_l _)).op), end, have hx : is_terminal x := { lift := λ s, begin fapply costruct...
def
Top.presheaf.pullback_obj_obj_of_image_open
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[ "is_open", "lift", "set.image_subset" ]
If `f '' U` is open, then `f⁻¹ℱ U ≅ ℱ (f '' U)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id : pullback_obj (𝟙 _) ℱ ≅ ℱ
nat_iso.of_components (λ U, pullback_obj_obj_of_image_open (𝟙 _) ℱ (unop U) (by simpa using U.unop.2) ≪≫ ℱ.map_iso (eq_to_iso (by simp))) (λ U V i, begin ext, simp, erw colimit.pre_desc_assoc, erw colimit.ι_desc_assoc, erw colimit.ι_desc_assoc, dsimp, simp only [←ℱ.map_comp], co...
def
Top.presheaf.pullback.id
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
The pullback along the identity is isomorphic to the original presheaf.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id_inv_app (U : opens Y) : (id ℱ).inv.app (op U) = colimit.ι (Lan.diagram (opens.map (𝟙 Y)).op ℱ (op U)) (@costructured_arrow.mk _ _ _ _ _ (op U) _ (eq_to_hom (by simp)))
begin rw [← category.id_comp ((id ℱ).inv.app (op U)), ← nat_iso.app_inv, iso.comp_inv_eq], dsimp [id], rw colimit.ι_desc_assoc, dsimp, rw [← ℱ.map_comp, ← ℱ.map_id], refl, end
lemma
Top.presheaf.pullback.id_inv_app
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward {X Y : Top.{w}} (f : X ⟶ Y) : X.presheaf C ⥤ Y.presheaf C
{ obj := pushforward_obj f, map := @pushforward_map _ _ X Y f }
def
Top.presheaf.pushforward
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
The pushforward functor.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pushforward_map_app' {X Y : Top.{w}} (f : X ⟶ Y) {ℱ 𝒢 : X.presheaf C} (α : ℱ ⟶ 𝒢) {U : (opens Y)ᵒᵖ} : ((pushforward C f).map α).app U = α.app (op $ (opens.map f).obj U.unop)
rfl
lemma
Top.presheaf.pushforward_map_app'
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
id_pushforward {X : Top.{w}} : pushforward C (𝟙 X) = 𝟭 (X.presheaf C)
begin apply category_theory.functor.ext, { intros, ext U, have h := f.congr, erw h (opens.op_map_id_obj U), simpa [eq_to_hom_map], }, { intros, apply pushforward.id_eq }, end
lemma
Top.presheaf.id_pushforward
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[ "category_theory.functor.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
presheaf_equiv_of_iso {X Y : Top} (H : X ≅ Y) : X.presheaf C ≌ Y.presheaf C
equivalence.congr_left (opens.map_map_iso H).symm.op
def
Top.presheaf.presheaf_equiv_of_iso
topology.sheaves
src/topology/sheaves/presheaf.lean
[ "category_theory.limits.kan_extension", "topology.category.Top.opens", "category_theory.adjunction.opposites" ]
[ "Top" ]
A homeomorphism of spaces gives an equivalence of categories of presheaves.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83