The monoidal category structure on simplicial sets #
This file defines an instance of chosen finite products
for the category SSet. It follows from the fact
the SSet if a category of functors to the category
of types and that the category of types have chosen
finite products. As a result, we obtain a monoidal
category structure on SSet.
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theorem SSet.leftUnitor_hom_app_apply (K : SSet) {Δ : SimplexCategoryᵒᵖ} (x : (CategoryTheory.MonoidalCategoryStruct.tensorObj (CategoryTheory.MonoidalCategoryStruct.tensorUnit SSet) K).obj Δ) :
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theorem SSet.rightUnitor_hom_app_apply (K : SSet) {Δ : SimplexCategoryᵒᵖ} (x : (CategoryTheory.MonoidalCategoryStruct.tensorObj K (CategoryTheory.MonoidalCategoryStruct.tensorUnit SSet)).obj Δ) :
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theorem SSet.tensorHom_app_apply {K K' L L' : SSet} (f : K ⟶ K') (g : L ⟶ L') {Δ : SimplexCategoryᵒᵖ} (x : (CategoryTheory.MonoidalCategoryStruct.tensorObj K L).obj Δ) :
(CategoryTheory.ConcreteCategory.hom (CategoryTheory.MonoidalCategoryStruct.tensorHom (f.app Δ) (g.app Δ))) x = ((CategoryTheory.ConcreteCategory.hom (f.app Δ)) x.1, (CategoryTheory.ConcreteCategory.hom (g.app Δ)) x.2)
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theorem SSet.whiskerLeft_app_apply (K : SSet) {L L' : SSet} (g : L ⟶ L') {Δ : SimplexCategoryᵒᵖ} (x : (CategoryTheory.MonoidalCategoryStruct.tensorObj K L).obj Δ) :
(CategoryTheory.ConcreteCategory.hom (CategoryTheory.MonoidalCategoryStruct.whiskerLeft (K.obj Δ) (g.app Δ))) x = (x.1, (CategoryTheory.ConcreteCategory.hom (g.app Δ)) x.2)
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theorem SSet.whiskerRight_app_apply {K K' : SSet} (f : K ⟶ K') (L : SSet) {Δ : SimplexCategoryᵒᵖ} (x : (CategoryTheory.MonoidalCategoryStruct.tensorObj K L).obj Δ) :
(CategoryTheory.ConcreteCategory.hom (CategoryTheory.MonoidalCategoryStruct.whiskerRight (f.app Δ) (L.obj Δ))) x = ((CategoryTheory.ConcreteCategory.hom (f.app Δ)) x.1, x.2)
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theorem SSet.associator_hom_app_apply (K L M : SSet) {Δ : SimplexCategoryᵒᵖ} (x : (CategoryTheory.MonoidalCategoryStruct.tensorObj (CategoryTheory.MonoidalCategoryStruct.tensorObj K L) M).obj Δ) :
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theorem SSet.associator_inv_app_apply (K L M : SSet) {Δ : SimplexCategoryᵒᵖ} (x : (CategoryTheory.MonoidalCategoryStruct.tensorObj K (CategoryTheory.MonoidalCategoryStruct.tensorObj L M)).obj Δ) :
The bijection (𝟙_ SSet ⟶ K) ≃ K _⦋0⦌.
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instance SSet.instFiniteObjOppositeSimplexCategoryTensorObj (X Y : SSet) (n : SimplexCategoryᵒᵖ) [Finite (X.obj n)] [Finite (Y.obj n)] :
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The external product of subcomplexes of simplicial sets.
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theorem SSet.Subcomplex.prod_obj {X Y : SSet} (A : X.Subcomplex) (B : Y.Subcomplex) (Δ : SimplexCategoryᵒᵖ) :
theorem SSet.Subcomplex.prod_monotone {X Y : SSet} {A₁ A₂ : X.Subcomplex} (hX : A₁ ≤ A₂) {B₁ B₂ : Y.Subcomplex} (hY : B₁ ≤ B₂) :
The isomorphism (A.prod B).toSSet ≅ A.toSSet ⊗ B.toSSet.
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theorem SSet.ι₀_comp_assoc {X Y : SSet} (f : X ⟶ Y) {Z : SSet} (h : CategoryTheory.MonoidalCategoryStruct.tensorObj Y (stdSimplex.obj { len := 1 }) ⟶ Z) :
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theorem SSet.ι₀_app_snd_apply {X : SSet} {m : ℕ} (x : X.obj (Opposite.op { len := m })) (k : Fin (m + 1)) :
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theorem SSet.ι₁_comp_assoc {X Y : SSet} (f : X ⟶ Y) {Z : SSet} (h : CategoryTheory.MonoidalCategoryStruct.tensorObj Y (stdSimplex.obj { len := 1 }) ⟶ Z) :
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theorem SSet.ι₁_app_snd_apply {X : SSet} {m : ℕ} (x : X.obj (Opposite.op { len := m })) (k : Fin (m + 1)) :
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theorem SSet.prod_map_fst (X Y : SSet) {m n : SimplexCategoryᵒᵖ} (f : m ⟶ n) (z : (CategoryTheory.MonoidalCategoryStruct.tensorObj X Y).obj m) :
((CategoryTheory.ConcreteCategory.hom (CategoryTheory.MonoidalCategoryStruct.tensorHom (X.map f) (Y.map f))) z).1 = (CategoryTheory.ConcreteCategory.hom (X.map f)) z.1
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theorem SSet.prod_map_snd (X Y : SSet) {m n : SimplexCategoryᵒᵖ} (f : m ⟶ n) (z : (CategoryTheory.MonoidalCategoryStruct.tensorObj X Y).obj m) :
((CategoryTheory.ConcreteCategory.hom (CategoryTheory.MonoidalCategoryStruct.tensorHom (X.map f) (Y.map f))) z).2 = (CategoryTheory.ConcreteCategory.hom (Y.map f)) z.2
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theorem SSet.prod_δ_fst (X Y : SSet) {n : ℕ} (i : Fin (n + 2)) (z : (CategoryTheory.MonoidalCategoryStruct.tensorObj X Y).obj (Opposite.op { len := n + 1 })) :
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theorem SSet.prod_δ_snd (X Y : SSet) {n : ℕ} (i : Fin (n + 2)) (z : (CategoryTheory.MonoidalCategoryStruct.tensorObj X Y).obj (Opposite.op { len := n + 1 })) :
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theorem SSet.prod_σ_fst (X Y : SSet) {n : ℕ} (i : Fin (n + 1)) (z : (CategoryTheory.MonoidalCategoryStruct.tensorObj X Y).obj (Opposite.op { len := n })) :
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theorem SSet.prod_σ_snd (X Y : SSet) {n : ℕ} (i : Fin (n + 1)) (z : (CategoryTheory.MonoidalCategoryStruct.tensorObj X Y).obj (Opposite.op { len := n })) :
Given S ≤ X and T ≤ Y, this is the subcomplex of X ⊗ Y given by (X ⊗ T) ⊔ (S ⊗ Y).
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theorem SSet.Subcomplex.mem_unionProd_iff {X Y : SSet} (S : X.Subcomplex) (T : Y.Subcomplex) {n : SimplexCategoryᵒᵖ} (x : (CategoryTheory.MonoidalCategoryStruct.tensorObj X Y).obj n) :
theorem SSet.Subcomplex.preimage_unionProd {X Y : SSet} (S : X.Subcomplex) (T : Y.Subcomplex) {X' Y' : SSet} (f : X' ⟶ X) (g : Y' ⟶ Y) :
The inclusion X ⊗ T ⟶ S.unionProd T as simplicial sets.
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The inclusion S ⊗ Y ⟶ S.unionProd T as simplicial sets
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theorem SSet.Subcomplex.unionProd.ι₁_ι_assoc {X Y : SSet} (S : X.Subcomplex) (T : Y.Subcomplex) {Z : SSet} (h : CategoryTheory.MonoidalCategoryStruct.tensorObj X Y ⟶ Z) :
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theorem SSet.Subcomplex.unionProd.ι₂_ι_assoc {X Y : SSet} (S : X.Subcomplex) (T : Y.Subcomplex) {Z : SSet} (h : CategoryTheory.MonoidalCategoryStruct.tensorObj X Y ⟶ Z) :
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theorem SSet.Subcomplex.unionProd.preimage_β_hom {X Y : SSet} (S : X.Subcomplex) (T : Y.Subcomplex) :
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theorem SSet.Subcomplex.unionProd.preimage_β_inv {X Y : SSet} (S : X.Subcomplex) (T : Y.Subcomplex) :
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noncomputable def SSet.Subcomplex.unionProd.symmIso {X Y : SSet} (S : X.Subcomplex) (T : Y.Subcomplex) :
The isomorphism unionProd S T ≅ unionProd T S as simplicial sets.
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theorem SSet.Truncated.tensor_map_apply_fst {n : ℕ} {X Y : Truncated n} {d e : (SimplexCategory.Truncated n)ᵒᵖ} (f : d ⟶ e) (x : (CategoryTheory.MonoidalCategoryStruct.tensorObj X Y).obj d) :
((CategoryTheory.ConcreteCategory.hom (CategoryTheory.MonoidalCategoryStruct.tensorHom (X.map f) (Y.map f))) x).1 = (CategoryTheory.ConcreteCategory.hom (X.map f)) x.1
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theorem SSet.Truncated.tensor_map_apply_snd {n : ℕ} {X Y : Truncated n} {d e : (SimplexCategory.Truncated n)ᵒᵖ} (f : d ⟶ e) (x : (CategoryTheory.MonoidalCategoryStruct.tensorObj X Y).obj d) :
((CategoryTheory.ConcreteCategory.hom (CategoryTheory.MonoidalCategoryStruct.tensorHom (X.map f) (Y.map f))) x).2 = (CategoryTheory.ConcreteCategory.hom (Y.map f)) x.2