mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.AlgebraicTopology.FundamentalGroupoid.InducedMaps

Goal state before:
pp: X Y : TopCat
f g : C(↑X, ↑Y)
H : f.Homotopy g
x₀ x₁ : ↑X
p : fromTop x₀ ⟶ fromTop x₁
p' : Path (fromTop x₀).as (fromTop x₁).as
t✝ : ↑I
⊢ g (p' t✝) = H.uliftMap ((fun t ↦ ((Path.refl { down := 1 }) t, p' t)) t✝)

Tactic:
ulift_apply H

Goal state after:
X Y : TopCat
f g : C(↑X, ↑Y)
H : f.Homotopy g
x₀ x₁ : ↑X
p : fromTop x₀ ⟶ fromTop x₁
p' : Path (fromTop x₀).as (fromTop x₁).as
t✝ : ↑I
⊢ g (p' t✝) = H (((Path.refl { down := 1 }) t✝).down, p' t✝)
Module: Mathlib.AlgebraicTopology.ModelCategory.FundamentalLemma

Goal state before:
pp: C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
inst✝⁴ : ModelCategory C
H : Type u_2
inst✝³ : Category.{v_2, u_2} H
L : C ⥤ H
inst✝² : L.IsLocalization (weakEquivalences C)
X Y : C
inst✝¹ : IsCofibrant X
inst✝ : IsFibrant Y
⊢ Function.Bijective (leftHomotopyClassToHom L) ↔ Function.Bijective (rightHomotopyClassToHom L)

Tactic:
have : (leftHomotopyClassToHom L : LeftHomotopyClass X Y → _) =
      rightHomotopyClassToHom L ∘ leftHomotopyClassEquivRightHomotopyClass := by
    ext f
    obtain ⟨f, rfl⟩ := f.mk_surjective
    simp

Goal state after:
C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
inst✝⁴ : ModelCategory C
H : Type u_2
inst✝³ : Category.{v_2, u_2} H
L : C ⥤ H
inst✝² : L.IsLocalization (weakEquivalences C)
X Y : C
inst✝¹ : IsCofibrant X
inst✝ : IsFibrant Y
this : leftHomotopyClassToHom L = rightHomotopyClassToHom L ∘ ⇑leftHomotopyClassEquivRightHomotopyClass
⊢ Function.Bijective (leftHomotopyClassToHom L) ↔ Function.Bijective (rightHomotopyClassToHom L)
Module: Mathlib.AlgebraicTopology.FundamentalGroupoid.Basic

Goal state before:
pp: case mk
X : Type u_1
inst✝ : TopologicalSpace X
x₀ x₁ : X
γ : Path x₀ x₁
⊢ (refl x₀).trans (mk γ) = mk γ

Tactic:
simpa [← mk_trans, ← mk_refl, eq] using Homotopic.refl_trans γ

Goal state after:
Module: Mathlib.CategoryTheory.Subfunctor.Equalizer

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
F₁ F₂ : C ⥤ Type w
A : Subfunctor F₁
f g : A.toFunctor ⟶ F₂
s : Limits.Fork f g
m : s.pt ⟶ (fork f g).pt
hm : m ≫ (fork f g).ι = s.ι
⊢ m = lift f g s.ι ⋯

Tactic:
by simp [← cancel_mono (Subfunctor.equalizer f g).ι, ← hm]

Goal state after:
Module: Mathlib.AlgebraicTopology.SimplicialSet.Boundary

Goal state before:
pp: case inr
n : ℕ
A : Δ[n].Subcomplex
h : A ≠ ⊤
hi : n ≤ n
a : Δ[n] _⦋n⦌
ha : a ∈ A.obj (op ⦋n⦌)
⊢ a ∈ Δ[n].degenerate n

Tactic:
rw [mem_degenerate_iff_notMem_nonDegenerate, nonDegenerate_top_dim]

Goal state after:
case inr
n : ℕ
A : Δ[n].Subcomplex
h : A ≠ ⊤
hi : n ≤ n
a : Δ[n] _⦋n⦌
ha : a ∈ A.obj (op ⦋n⦌)
⊢ a ∉ {objEquiv.symm (𝟙 (unop (op ⦋n⦌)))}
Module: Mathlib.AlgebraicTopology.SimplicialSet.Skeleton

Goal state before:
pp: X Y : SSet
i : X ⟶ Y
d : ℕ
x✝ : SimplexCategoryᵒᵖ
n : ℕ
c₁ : Cell i d
f₁ : ⦋n⦌ ⟶ ⦋d⦌
w✝¹ : Epi f₁
hx₁ :
  (ConcreteCategory.hom (c₁.ιSigmaStdSimplex.app (op ⦋n⦌))) (stdSimplex.objEquiv.symm f₁) ∉
    Set.range ⇑(ConcreteCategory.hom ((l i d).app (op ⦋n⦌)))
c₂ : Cell i d
f₂ : ⦋n⦌ ⟶ ⦋d⦌
w✝ : Epi f₂
hx₂ :
  (ConcreteCategory.hom (c₂.ιSigmaStdSimplex.app (op ⦋n⦌))) (stdSimplex.objEquiv.symm f₂) ∉
    Set.range ⇑(ConcreteCategory.hom ((l i d).app (op ⦋n⦌)))
h :
  ↑((ConcreteCategory.hom ((b i d).app (op ⦋n⦌)))
        ((ConcreteCategory.hom (c₁.ιSigmaStdSimplex.app (op ⦋n⦌))) (stdSimplex.objEquiv.symm f₁))) =
    ↑((ConcreteCategory.hom ((b i d).app (op ⦋n⦌)))
        ((ConcreteCategory.hom (c₂.ιSigmaStdSimplex.app (op ⦋n⦌))) (stdSimplex.objEquiv.symm f₂)))
⊢ (ConcreteCategory.hom (Y.map f₁.op)) c₁.simplex = (ConcreteCategory.hom (Y.map f₂.op)) c₂.simplex

Tactic:
← c₁.b_app_ι_app_objEquiv_symm_val f₁,

Goal state after:
X Y : SSet
i : X ⟶ Y
d : ℕ
x✝ : SimplexCategoryᵒᵖ
n : ℕ
c₁ : Cell i d
f₁ : ⦋n⦌ ⟶ ⦋d⦌
w✝¹ : Epi f₁
hx₁ :
  (ConcreteCategory.hom (c₁.ιSigmaStdSimplex.app (op ⦋n⦌))) (stdSimplex.objEquiv.symm f₁) ∉
    Set.range ⇑(ConcreteCategory.hom ((l i d).app (op ⦋n⦌)))
c₂ : Cell i d
f₂ : ⦋n⦌ ⟶ ⦋d⦌
w✝ : Epi f₂
hx₂ :
  (ConcreteCategory.hom (c₂.ιSigmaStdSimplex.app (op ⦋n⦌))) (stdSimplex.objEquiv.symm f₂) ∉
    Set.range ⇑(ConcreteCategory.hom ((l i d).app (op ⦋n⦌)))
h :
  ↑((ConcreteCategory.hom ((b i d).app (op ⦋n⦌)))
        ((ConcreteCategory.hom (c₁.ιSigmaStdSimplex.app (op ⦋n⦌))) (stdSimplex.objEquiv.symm f₁))) =
    ↑((ConcreteCategory.hom ((b i d).app (op ⦋n⦌)))
        ((ConcreteCategory.hom (c₂.ιSigmaStdSimplex.app (op ⦋n⦌))) (stdSimplex.objEquiv.symm f₂)))
⊢ ↑((ConcreteCategory.hom ((b i d).app (op ⦋n⦌)))
        ((ConcreteCategory.hom (c₁.ιSigmaStdSimplex.app (op ⦋n⦌))) (stdSimplex.objEquiv.symm f₁))) =
    (ConcreteCategory.hom (Y.map f₂.op)) c₂.simplex
Module: Mathlib.CategoryTheory.Monoidal.Cartesian.Cat

Goal state before:
pp: X Y : Cat
x✝⁴ : BinaryFan X Y
x✝³ : x✝⁴.pt ⟶ of (↑X × ↑Y)
h1 : x✝³ ≫ (Prod.fst ↑X ↑Y).toCatHom = x✝⁴.fst
h2 : x✝³ ≫ (Prod.snd ↑X ↑Y).toCatHom = x✝⁴.snd
x✝² x✝¹ : ↑x✝⁴.pt
x✝ : x✝² ⟶ x✝¹
⊢ x✝³.toFunctor.map x✝ ≍ Prod.mkHom (x✝⁴.fst.toFunctor.map x✝) (x✝⁴.snd.toFunctor.map x✝)

Tactic:
← h1,

Goal state after:
X Y : Cat
x✝⁴ : BinaryFan X Y
x✝³ : x✝⁴.pt ⟶ of (↑X × ↑Y)
h1 : x✝³ ≫ (Prod.fst ↑X ↑Y).toCatHom = x✝⁴.fst
h2 : x✝³ ≫ (Prod.snd ↑X ↑Y).toCatHom = x✝⁴.snd
x✝² x✝¹ : ↑x✝⁴.pt
x✝ : x✝² ⟶ x✝¹
⊢ x✝³.toFunctor.map x✝ ≍ Prod.mkHom ((x✝³ ≫ (Prod.fst ↑X ↑Y).toCatHom).toFunctor.map x✝) (x✝⁴.snd.toFunctor.map x✝)
Module: Mathlib.AlgebraicTopology.Quasicategory.StrictSegal

Goal state before:
pp: case h.inr.inr.succ
X : SSet
sx : X.StrictSegal
n : ℕ
i : Fin (n + 1 + 3)
σ₀ : Λ[n + 1 + 2, i].toSSet ⟶ X
h₀ : 0 < i
hₙ : i < Fin.last (n + 1 + 2)
j : Fin (n + 1 + 3)
hj : j ≠ i
k : Fin (n + 1 + 1)
ksucc : Fin (n + 1 + 1 + 1 + 1) := k.succ.castSucc
heq : j = ksucc
triangle : Λ[n + 3, i].toSSet _⦋2⦌ := horn.primitiveTriangle i h₀ hₙ ↑k ⋯
hi :
  ((horn.spineId i h₀ hₙ).map σ₀).interval (↑k) 2 ⋯ =
    X.spine 2 ((ConcreteCategory.hom (σ₀.app (Opposite.op ⦋2⦌))) triangle)
z : Fin (1 + 1)
⊢ (stdSimplex.objEquiv.symm (diag 2 ≫ stdSimplex.objEquiv ↑triangle)) z =
    (stdSimplex.objEquiv.symm (mkOfSucc k ≫ stdSimplex.objEquiv (stdSimplex.objEquiv.symm (SimplexCategory.δ j)))) z

Tactic:
simp only [Equiv.apply_symm_apply, triangle]

Goal state after:
case h.inr.inr.succ
X : SSet
sx : X.StrictSegal
n : ℕ
i : Fin (n + 1 + 3)
σ₀ : Λ[n + 1 + 2, i].toSSet ⟶ X
h₀ : 0 < i
hₙ : i < Fin.last (n + 1 + 2)
j : Fin (n + 1 + 3)
hj : j ≠ i
k : Fin (n + 1 + 1)
ksucc : Fin (n + 1 + 1 + 1 + 1) := k.succ.castSucc
heq : j = ksucc
triangle : Λ[n + 3, i].toSSet _⦋2⦌ := horn.primitiveTriangle i h₀ hₙ ↑k ⋯
hi :
  ((horn.spineId i h₀ hₙ).map σ₀).interval (↑k) 2 ⋯ =
    X.spine 2 ((ConcreteCategory.hom (σ₀.app (Opposite.op ⦋2⦌))) triangle)
z : Fin (1 + 1)
⊢ (stdSimplex.objEquiv.symm (diag 2 ≫ stdSimplex.objEquiv ↑(horn.primitiveTriangle i h₀ hₙ ↑k ⋯))) z =
    (stdSimplex.objEquiv.symm (mkOfSucc k ≫ SimplexCategory.δ j)) z
Module: Mathlib.CategoryTheory.Bicategory.CatEnriched

Goal state before:
pp: C : Type u
inst✝¹ : Category.{v, u} C
inst✝ : EnrichedOrdinaryCategory Cat C
a b c : CatEnrichedOrdinary C
f : a ⟶ b
g : b ⟶ c
⊢ hComp (𝟙 f) (𝟙 g) = 𝟙 (f ≫ g)

Tactic:
simp [hComp, Hom.id_eq]

Goal state after:
Module: Mathlib.CategoryTheory.Monoidal.Center

Goal state before:
pp: C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
inst✝ : MonoidalCategory C
X Y : Center C
U U' : C
f : U ⟶ U'
⊢ 𝟙 ((X.fst ⊗ Y.fst) ⊗ U) ⊗≫
      X.fst ◁ (Y.fst ◁ f ≫ (Y.snd.β U').hom) ⊗≫ (X.snd.β U').hom ▷ Y.fst ⊗≫ 𝟙 (U' ⊗ X.fst ⊗ Y.fst) =
    𝟙 ((X.fst ⊗ Y.fst) ⊗ U) ⊗≫
      X.fst ◁ (Y.snd.β U).hom ⊗≫ (X.fst ◁ f ≫ (X.snd.β U').hom) ▷ Y.fst ⊗≫ 𝟙 (U' ⊗ X.fst ⊗ Y.fst)

Tactic:
HalfBraiding.naturality

Goal state after:
C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
inst✝ : MonoidalCategory C
X Y : Center C
U U' : C
f : U ⟶ U'
⊢ 𝟙 ((X.fst ⊗ Y.fst) ⊗ U) ⊗≫
      X.fst ◁ ((Y.snd.β U).hom ≫ f ▷ Y.fst) ⊗≫ (X.snd.β U').hom ▷ Y.fst ⊗≫ 𝟙 (U' ⊗ X.fst ⊗ Y.fst) =
    𝟙 ((X.fst ⊗ Y.fst) ⊗ U) ⊗≫
      X.fst ◁ (Y.snd.β U).hom ⊗≫ (X.fst ◁ f ≫ (X.snd.β U').hom) ▷ Y.fst ⊗≫ 𝟙 (U' ⊗ X.fst ⊗ Y.fst)
Module: Mathlib.CategoryTheory.Monoidal.Center

Goal state before:
pp: C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
inst✝ : MonoidalCategory C
X Y : Center C
U U' : C
f : U ⟶ U'
⊢ 𝟙 ((X.fst ⊗ Y.fst) ⊗ U) ⊗≫
      X.fst ◁ (Y.snd.β U).hom ⊗≫ (X.fst ◁ f ≫ (X.snd.β U').hom) ▷ Y.fst ⊗≫ 𝟙 (U' ⊗ X.fst ⊗ Y.fst) =
    ((α_ X.fst Y.fst U).hom ≫
        X.fst ◁ (Y.snd.β U).hom ≫ (α_ X.fst U Y.fst).inv ≫ (X.snd.β U).hom ▷ Y.fst ≫ (α_ U X.fst Y.fst).hom) ≫
      f ▷ (X.fst ⊗ Y.fst)

Tactic:
HalfBraiding.naturality

Goal state after:
C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
inst✝ : MonoidalCategory C
X Y : Center C
U U' : C
f : U ⟶ U'
⊢ 𝟙 ((X.fst ⊗ Y.fst) ⊗ U) ⊗≫
      X.fst ◁ (Y.snd.β U).hom ⊗≫ ((X.snd.β U).hom ≫ f ▷ X.fst) ▷ Y.fst ⊗≫ 𝟙 (U' ⊗ X.fst ⊗ Y.fst) =
    ((α_ X.fst Y.fst U).hom ≫
        X.fst ◁ (Y.snd.β U).hom ≫ (α_ X.fst U Y.fst).inv ≫ (X.snd.β U).hom ▷ Y.fst ≫ (α_ U X.fst Y.fst).hom) ≫
      f ▷ (X.fst ⊗ Y.fst)
Module: Mathlib.AlgebraicTopology.SimplicialSet.Monoidal

Goal state before:
pp: X Y : SSet
A : X.Subcomplex
B : Y.Subcomplex
⊢ range (A.ι ⊗ₘ B.ι) ≤ A.prod B

Tactic:
rintro m _ ⟨⟨y₁, y₂⟩, ⟨⟩⟩

Goal state after:
X Y : SSet
A : X.Subcomplex
B : Y.Subcomplex
m : SimplexCategoryᵒᵖ
y₁ : A.toSSet.obj m
y₂ : B.toSSet.obj m
⊢ (ConcreteCategory.hom ((A.ι ⊗ₘ B.ι).app m)) (y₁, y₂) ∈ (A.prod B).obj m
Module: Mathlib.AlgebraicTopology.SimplicialSet.Monoidal

Goal state before:
pp: X Y : SSet
S : X.Subcomplex
T : Y.Subcomplex
⊢ range (X ◁ T.ι) ≤ S.unionProd T

Tactic:
rintro m _ ⟨⟨y₁, y₂⟩, ⟨⟩⟩

Goal state after:
X Y : SSet
S : X.Subcomplex
T : Y.Subcomplex
m : SimplexCategoryᵒᵖ
y₁ : X.obj m
y₂ : T.toSSet.obj m
⊢ (ConcreteCategory.hom ((X ◁ T.ι).app m)) (y₁, y₂) ∈ (S.unionProd T).obj m
Module: Mathlib.AlgebraicTopology.SimplicialSet.Monoidal

Goal state before:
pp: X Y : SSet
S : X.Subcomplex
T : Y.Subcomplex
⊢ range (S.ι ▷ Y) ≤ S.unionProd T

Tactic:
rintro m _ ⟨⟨y₁, y₂⟩, ⟨⟩⟩

Goal state after:
X Y : SSet
S : X.Subcomplex
T : Y.Subcomplex
m : SimplexCategoryᵒᵖ
y₁ : S.toSSet.obj m
y₂ : Y.obj m
⊢ (ConcreteCategory.hom ((S.ι ▷ Y).app m)) (y₁, y₂) ∈ (S.unionProd T).obj m
Module: Mathlib.AlgebraicTopology.Quasicategory.TwoTruncated

Goal state before:
pp: A : Truncated 2
inst✝ : A.Quasicategory₂
x y z : A.obj (Opposite.op { obj := { len := 0 }, property := Quasicategory₂._proof_1 })
f f' : Edge x y
g g' : Edge y z
h h' : Edge x z
s : f.CompStruct g h
s' : f'.CompStruct g' h'
hg✝ : HomotopicL g g'
hg : (id y).CompStruct g g'
hf : f.CompStruct (id y) f'
s₁ : f.CompStruct g' h'
⊢ HomotopicL h h'

Tactic:
let ⟨s₂⟩ := Quasicategory₂.fill31 (compId f) hg s₁

Goal state after:
A : Truncated 2
inst✝ : A.Quasicategory₂
x y z : A.obj (Opposite.op { obj := { len := 0 }, property := Quasicategory₂._proof_1 })
f f' : Edge x y
g g' : Edge y z
h h' : Edge x z
s : f.CompStruct g h
s' : f'.CompStruct g' h'
hg✝ : HomotopicL g g'
hg : (id y).CompStruct g g'
hf : f.CompStruct (id y) f'
s₁ : f.CompStruct g' h'
s₂ : f.CompStruct g h'
⊢ HomotopicL h h'
Module: Mathlib.AlgebraicTopology.SimplicialSet.HomotopyCat

Goal state before:
pp: V W x✝ : Truncated 2
⊢ (mapHomotopyCategory (𝟙 x✝)).toCatHom = 𝟙 (Cat.of x✝.HomotopyCategory)

Tactic:
ext1; exact HomotopyCategory.functor_ext (by simp) (by cat_disch)

Goal state after:
Module: Mathlib.AlgebraicTopology.SimplicialSet.HomotopyCat

Goal state before:
pp: V W X✝ Y✝ Z✝ : Truncated 2
x✝¹ : X✝ ⟶ Y✝
x✝ : Y✝ ⟶ Z✝
⊢ (mapHomotopyCategory (x✝¹ ≫ x✝)).toCatHom = (mapHomotopyCategory x✝¹).toCatHom ≫ (mapHomotopyCategory x✝).toCatHom

Tactic:
ext1; exact HomotopyCategory.functor_ext (by simp) (by cat_disch)

Goal state after:
Module: Mathlib.AlgebraicTopology.SimplexCategory.GeneratorsRelations.NormalForms

Goal state before:
pp: case cons
L : List ℕ
j head✝ : ℕ
tail✝ : List ℕ
tail_ih✝ : (∀ k ∈ tail✝, j ≤ k) → simplicialEvalσ tail✝ j = j
hj : ∀ k ∈ head✝ :: tail✝, j ≤ k
⊢ simplicialEvalσ (head✝ :: tail✝) j = j

Tactic:
simp only [List.forall_mem_cons] at hj; grind

Goal state after:
Module: Mathlib.AlgebraicTopology.SimplexCategory.ToMkOne

Goal state before:
pp: n : ℕ
j i : Fin (n + 2)
h✝ : i.castSucc ≤ j.castSucc
h : i ≤ j
k : Fin (⦋n⦌.len + 1)
⊢ (ConcreteCategory.hom (δ j ≫ toMk₁ i.castSucc)) k = (ConcreteCategory.hom (toMk₁ i)) k

Tactic:
change toMk₁ i.castSucc (j.succAbove k) = _

Goal state after:
n : ℕ
j i : Fin (n + 2)
h✝ : i.castSucc ≤ j.castSucc
h : i ≤ j
k : Fin (⦋n⦌.len + 1)
⊢ (ConcreteCategory.hom (toMk₁ i.castSucc)) (j.succAbove k) = (ConcreteCategory.hom (toMk₁ i)) k
Module: Mathlib.AlgebraicTopology.SimplexCategory.Augmented.Monoidal

Goal state before:
pp: x₁✝ y₁✝ x₂✝ y₂✝ : AugmentedSimplexCategory
f₁✝ : x₁✝ ⟶ y₁✝
f₂✝ : x₂✝ ⟶ y₂✝
x₁ y₁ x₂ y₂ : SimplexCategory
f₁ : WithInitial.of x₁ ⟶ WithInitial.of y₁
f₂ : WithInitial.of x₂ ⟶ WithInitial.of y₂
i : Fin (x₂.len + 1)
e₁ : (SimplexCategory.Hom.toOrderHom (inr' x₁ x₂)) i = Fin.cast ⋯ (Fin.natAdd x₁.len.succ i)
e₂ :
  (SimplexCategory.Hom.toOrderHom (inr' y₁ y₂)) ((SimplexCategory.Hom.toOrderHom (WithInitial.down f₂)) i) =
    Fin.cast ⋯ (Fin.natAdd y₁.len.succ ((SimplexCategory.Hom.toOrderHom (WithInitial.down f₂)) i))
⊢ {
        toFun := fun i ↦
          Fin.addCases (fun i ↦ Fin.castAdd (y₂.len + 1) ((SimplexCategory.Hom.toOrderHom f₁) i))
            (fun i ↦ Fin.natAdd (y₁.len + 1) ((SimplexCategory.Hom.toOrderHom f₂) i)) i,
        monotone' := ⋯ }
      (Fin.natAdd (x₁.len + 1) i) =
    Fin.natAdd (y₁.len + 1) ((SimplexCategory.Hom.toOrderHom (WithInitial.down f₂)) i)

Tactic:
conv_lhs =>
      change Fin.addCases
        (fun i ↦ Fin.castAdd (y₂.len + 1) (f₁.toOrderHom i))
        (fun i ↦ Fin.natAdd (y₁.len + 1) (f₂.toOrderHom i))
        (Fin.natAdd (x₁.len + 1) i)
      rw [Fin.addCases_right]

Goal state after:
x₁✝ y₁✝ x₂✝ y₂✝ : AugmentedSimplexCategory
f₁✝ : x₁✝ ⟶ y₁✝
f₂✝ : x₂✝ ⟶ y₂✝
x₁ y₁ x₂ y₂ : SimplexCategory
f₁ : WithInitial.of x₁ ⟶ WithInitial.of y₁
f₂ : WithInitial.of x₂ ⟶ WithInitial.of y₂
i : Fin (x₂.len + 1)
e₁ : (SimplexCategory.Hom.toOrderHom (inr' x₁ x₂)) i = Fin.cast ⋯ (Fin.natAdd x₁.len.succ i)
e₂ :
  (SimplexCategory.Hom.toOrderHom (inr' y₁ y₂)) ((SimplexCategory.Hom.toOrderHom (WithInitial.down f₂)) i) =
    Fin.cast ⋯ (Fin.natAdd y₁.len.succ ((SimplexCategory.Hom.toOrderHom (WithInitial.down f₂)) i))
⊢ Fin.natAdd (y₁.len + 1) ((SimplexCategory.Hom.toOrderHom f₂) i) =
    Fin.natAdd (y₁.len + 1) ((SimplexCategory.Hom.toOrderHom (WithInitial.down f₂)) i)
Module: Mathlib.AlgebraicTopology.SimplicialSet.Nonsingular

Goal state before:
pp: X : SSet
inst✝ : X.Nonsingular
n : ℕ
x : X _⦋n + 1⦌
hx : x ∈ X.nonDegenerate (n + 1)
i : Fin (n + 2)
this✝ : Mono (yonedaEquiv.symm x)
this :
  (ConcreteCategory.hom (SimplicialObject.δ X i)) x =
    (ConcreteCategory.hom ((yonedaEquiv.symm x).app (op ⦋n⦌))) (stdSimplex.objEquiv.symm (SimplexCategory.δ i))
⊢ stdSimplex.objEquiv.symm (SimplexCategory.δ i) ∈ Δ[n + 1].nonDegenerate n

Tactic:
stdSimplex.mem_nonDegenerate_iff_mono,

Goal state after:
X : SSet
inst✝ : X.Nonsingular
n : ℕ
x : X _⦋n + 1⦌
hx : x ∈ X.nonDegenerate (n + 1)
i : Fin (n + 2)
this✝ : Mono (yonedaEquiv.symm x)
this :
  (ConcreteCategory.hom (SimplicialObject.δ X i)) x =
    (ConcreteCategory.hom ((yonedaEquiv.symm x).app (op ⦋n⦌))) (stdSimplex.objEquiv.symm (SimplexCategory.δ i))
⊢ Mono (stdSimplex.objEquiv (stdSimplex.objEquiv.symm (SimplexCategory.δ i)))
Module: Mathlib.AlgebraicTopology.SimplicialSet.AnodyneExtensions.Rank

Goal state before:
pp: X : SSet
A : X.Subcomplex
h : A.PairingCore
α : Type v
inst✝² : PartialOrder α
inst✝¹ : WellFoundedLT α
inst✝ : h.IsProper
f : h.RankFunction α
⊢ h.IsRegular

Tactic:
rw [← isRegular_pairing_iff]

Goal state after:
X : SSet
A : X.Subcomplex
h : A.PairingCore
α : Type v
inst✝² : PartialOrder α
inst✝¹ : WellFoundedLT α
inst✝ : h.IsProper
f : h.RankFunction α
⊢ h.pairing.IsRegular
Module: Mathlib.AlgebraicTopology.SimplicialSet.AnodyneExtensions.Rank

Goal state before:
pp: X : SSet
A : X.Subcomplex
h : A.PairingCore
α : Type v
inst✝² : PartialOrder α
inst✝¹ : WellFoundedLT α
inst✝ : h.IsProper
f : h.WeakRankFunction α
⊢ h.IsRegular

Tactic:
rw [← isRegular_pairing_iff]

Goal state after:
X : SSet
A : X.Subcomplex
h : A.PairingCore
α : Type v
inst✝² : PartialOrder α
inst✝¹ : WellFoundedLT α
inst✝ : h.IsProper
f : h.WeakRankFunction α
⊢ h.pairing.IsRegular
Module: Mathlib.AlgebraicTopology.SimplicialSet.FiniteProd

Goal state before:
pp: X₁ X₂ : SSet
m : SimplexCategoryᵒᵖ
x₁ : X₁.obj m
x₂ : X₂.obj m
hx₁ : x₁ ∈ ⊤.obj m
⊢ ∃ i i_1, (x₁, x₂) ∈ ((Subcomplex.ofSimplex i.simplex).obj m).prod ((Subcomplex.ofSimplex i_1.simplex).obj m)

Tactic:
have hx₂ : x₂ ∈ (⊤ : X₂.Subcomplex).obj _ := by simp

Goal state after:
X₁ X₂ : SSet
m : SimplexCategoryᵒᵖ
x₁ : X₁.obj m
x₂ : X₂.obj m
hx₁ : x₁ ∈ ⊤.obj m
hx₂ : x₂ ∈ ⊤.obj m
⊢ ∃ i i_1, (x₁, x₂) ∈ ((Subcomplex.ofSimplex i.simplex).obj m).prod ((Subcomplex.ofSimplex i_1.simplex).obj m)
Module: Mathlib.AlgebraicTopology.SimplicialSet.AnodyneExtensions.RelativeCellComplex

Goal state before:
pp: X : SSet
A : X.Subcomplex
P : A.Pairing
ι : Type v
inst✝ : LinearOrder ι
f : P.RankFunction ι
i₁ i₂ : ι
h : i₁ ≤ i₂
j : ι
hj : j < i₁
c : f.Cell j
⊢ (↑(P.p c.s)).subcomplex ≤ f.filtration i₂

Tactic:
exact f.subcomplex_le_filtration c (lt_of_lt_of_le hj h)

Goal state after:
Module: Mathlib.AlgebraicTopology.SimplicialSet.AnodyneExtensions.RelativeCellComplex

Goal state before:
pp: X : SSet
A : X.Subcomplex
P : A.Pairing
ι : Type v
inst✝ : LinearOrder ι
f : P.RankFunction ι
j : ι
c : f.Cell j
i : ι
hi : i < j
c' : f.Cell i
h : (↑c.s).simplex ∈ (↑(P.p c'.s)).subcomplex.obj (op ⦋(↑c.s).dim⦌)
⊢ False

Tactic:
rw [← c.rank_s, ← c'.rank_s] at hi

Goal state after:
X : SSet
A : X.Subcomplex
P : A.Pairing
ι : Type v
inst✝ : LinearOrder ι
f : P.RankFunction ι
j : ι
c : f.Cell j
i : ι
c' : f.Cell i
hi : f.rank c'.s < f.rank c.s
h : (↑c.s).simplex ∈ (↑(P.p c'.s)).subcomplex.obj (op ⦋(↑c.s).dim⦌)
⊢ False
Module: Mathlib.CategoryTheory.Presentable.Retracts

Goal state before:
pp: case refine_2
C : Type u
inst✝² : Category.{v, u} C
X Y : C
h : Retract Y X
κ : Cardinal.{w}
inst✝¹ : Fact κ.IsRegular
inst✝ : IsCardinalPresentable X κ
J : Type w
x✝¹ : SmallCategory J
x✝ : IsCardinalFiltered J κ
F : J ⥤ C
c : Cocone F
hc : IsColimit c
this✝ : EssentiallySmall.{w, w, w} J
this : IsFiltered J
j : J
f₁ f₂ : (fun X ↦ X) ((F ⋙ coyoneda.obj (Opposite.op Y)).obj j)
hf :
  (ConcreteCategory.hom (((coyoneda.obj (Opposite.op Y)).mapCocone c).ι.app j)) f₁ =
    (ConcreteCategory.hom (((coyoneda.obj (Opposite.op Y)).mapCocone c).ι.app j)) f₂
⊢ ∃ k f,
    (ConcreteCategory.hom ((F ⋙ coyoneda.obj (Opposite.op Y)).map f)) f₁ =
      (ConcreteCategory.hom ((F ⋙ coyoneda.obj (Opposite.op Y)).map f)) f₂

Tactic:
dsimp at f₁ f₂ hf ⊢

Goal state after:
case refine_2
C : Type u
inst✝² : Category.{v, u} C
X Y : C
h : Retract Y X
κ : Cardinal.{w}
inst✝¹ : Fact κ.IsRegular
inst✝ : IsCardinalPresentable X κ
J : Type w
x✝¹ : SmallCategory J
x✝ : IsCardinalFiltered J κ
F : J ⥤ C
c : Cocone F
hc : IsColimit c
this✝ : EssentiallySmall.{w, w, w} J
this : IsFiltered J
j : J
f₁ f₂ : Y ⟶ F.obj j
hf : f₁ ≫ c.ι.app j = f₂ ≫ c.ι.app j
⊢ ∃ k f, f₁ ≫ F.map f = f₂ ≫ F.map f
Module: Mathlib.CategoryTheory.Presentable.Limits

Goal state before:
pp: C : Type u
inst✝⁴ : Category.{v, u} C
K : Type u'
inst✝³ : Category.{v', u'} K
F : K ⥤ C ⥤ Type w'
c : Cone F
hc : (Y : C) → IsLimit (((evaluation C (Type w')).obj Y).mapCone c)
κ : Cardinal.{w}
inst✝² : Fact κ.IsRegular
hK : HasCardinalLT (Arrow K) κ
J : Type w
inst✝¹ : SmallCategory J
inst✝ : IsCardinalFiltered J κ
X : J ⥤ C
cX : Cocone X
hF : (k : K) → IsColimit ((F.obj k).mapCocone cX)
x : c.pt.obj cX.pt
this : IsFiltered J
y : ↑(F ⋙ (evaluation C (Type w')).obj cX.pt).sections
hy : (Types.isLimitEquivSections (hc cX.pt)).symm y = x
j₀ : J
z : (k : K) → (F.obj k).obj (X.obj j₀)
hz : ∀ (k : K), ↑y k = (ConcreteCategory.hom ((F.obj k).map (cX.ι.app j₀))) (z k)
k k' : K
φ : k ⟶ k'
⊢ (ConcreteCategory.hom (((F.obj k').mapCocone cX).ι.app j₀))
      ((ConcreteCategory.hom ((F.map φ).app (X.obj j₀))) (z k)) =
    (ConcreteCategory.hom (((F.obj k').mapCocone cX).ι.app j₀)) (z k')

Tactic:
dsimp at hz ⊢

Goal state after:
C : Type u
inst✝⁴ : Category.{v, u} C
K : Type u'
inst✝³ : Category.{v', u'} K
F : K ⥤ C ⥤ Type w'
c : Cone F
hc : (Y : C) → IsLimit (((evaluation C (Type w')).obj Y).mapCone c)
κ : Cardinal.{w}
inst✝² : Fact κ.IsRegular
hK : HasCardinalLT (Arrow K) κ
J : Type w
inst✝¹ : SmallCategory J
inst✝ : IsCardinalFiltered J κ
X : J ⥤ C
cX : Cocone X
hF : (k : K) → IsColimit ((F.obj k).mapCocone cX)
x : c.pt.obj cX.pt
this : IsFiltered J
y : ↑(F ⋙ (evaluation C (Type w')).obj cX.pt).sections
hy : (Types.isLimitEquivSections (hc cX.pt)).symm y = x
j₀ : J
z : (k : K) → (F.obj k).obj (X.obj j₀)
hz : ∀ (k : K), ↑y k = (ConcreteCategory.hom ((F.obj k).map (cX.ι.app j₀))) (z k)
k k' : K
φ : k ⟶ k'
⊢ (ConcreteCategory.hom ((F.obj k').map (cX.ι.app j₀))) ((ConcreteCategory.hom ((F.map φ).app (X.obj j₀))) (z k)) =
    (ConcreteCategory.hom ((F.obj k').map (cX.ι.app j₀))) (z k')
Module: Mathlib.AlgebraicTopology.SimplicialSet.AnodyneExtensions.RelativeCellComplex

Goal state before:
pp: X : SSet
A : X.Subcomplex
P : A.Pairing
ι : Type v
inst✝¹ : LinearOrder ι
f : P.RankFunction ι
inst✝ : P.IsProper
j : ι
c : f.Cell j
⊢ stdSimplex.objEquiv.symm (𝟙 (unop (op ⦋c.dim + 1⦌))) ∈ Δ[c.dim + 1].nonDegenerate (c.dim + 1)

Tactic:
stdSimplex.mem_nonDegenerate_iff_mono,

Goal state after:
X : SSet
A : X.Subcomplex
P : A.Pairing
ι : Type v
inst✝¹ : LinearOrder ι
f : P.RankFunction ι
inst✝ : P.IsProper
j : ι
c : f.Cell j
⊢ Mono (stdSimplex.objEquiv (stdSimplex.objEquiv.symm (𝟙 (unop (op ⦋c.dim + 1⦌)))))
Module: Mathlib.AlgebraicTopology.SimplicialSet.AnodyneExtensions.RelativeCellComplex

Goal state before:
pp: X : SSet
A : X.Subcomplex
P : A.Pairing
ι : Type v
inst✝¹ : LinearOrder ι
f : P.RankFunction ι
inst✝ : P.IsProper
j : ι
c : f.Cell j
⊢ stdSimplex.objEquiv.symm (SimplexCategory.δ c.index) ∈ Δ[c.dim + 1].nonDegenerate c.dim

Tactic:
stdSimplex.mem_nonDegenerate_iff_mono,

Goal state after:
X : SSet
A : X.Subcomplex
P : A.Pairing
ι : Type v
inst✝¹ : LinearOrder ι
f : P.RankFunction ι
inst✝ : P.IsProper
j : ι
c : f.Cell j
⊢ Mono (stdSimplex.objEquiv (stdSimplex.objEquiv.symm (SimplexCategory.δ c.index)))
Module: Mathlib.AlgebraicTopology.SimplicialSet.AnodyneExtensions.RelativeCellComplex

Goal state before:
pp: X : SSet
A : X.Subcomplex
P : A.Pairing
ι : Type v
inst✝¹ : LinearOrder ι
f : P.RankFunction ι
inst✝ : P.IsProper
j : ι
x' : f.Cell j
hy' : stdSimplex.objEquiv.symm (SimplexCategory.δ x'.index) ∈ x'.horn.obj (op ⦋x'.dim⦌)
⊢ False

Tactic:
simpa using (objEquiv_symm_δ_mem_horn_iff _ _).mp hy'

Goal state after:
Module: Mathlib.AlgebraicTopology.SimplicialSet.AnodyneExtensions.RelativeCellComplex

Goal state before:
pp: X : SSet
A : X.Subcomplex
P : A.Pairing
ι : Type v
inst✝¹ : LinearOrder ι
f : P.RankFunction ι
inst✝ : P.IsProper
j : ι
d : ℕ
x : f.Cell j
g : unop (op ⦋d⦌) ⟶ ⦋x.dim + 1⦌
hs✝ :
  (ConcreteCategory.hom (x.ιSigmaStdSimplex.app (op ⦋d⦌))) (stdSimplex.objEquiv.symm g) ∈
    (f.sigmaStdSimplex j).nonDegenerate d
hs : stdSimplex.objEquiv.symm g ∈ Δ[x.dim + 1].nonDegenerate d
hs'✝ :
  (ConcreteCategory.hom (x.ιSigmaStdSimplex.app (op ⦋d⦌))) (stdSimplex.objEquiv.symm g) ∉ (range (f.m j)).obj (op ⦋d⦌)
hs' : stdSimplex.objEquiv.symm g ∉ Λ[x.dim + 1, x.index].obj (op ⦋d⦌)
⊢ ∃ c,
    N.mk ((ConcreteCategory.hom (x.ιSigmaStdSimplex.app (op ⦋d⦌))) (stdSimplex.objEquiv.symm g)) hs✝ hs'✝ =
        Cell.type₁ f c ∨
      N.mk ((ConcreteCategory.hom (x.ιSigmaStdSimplex.app (op ⦋d⦌))) (stdSimplex.objEquiv.symm g)) hs✝ hs'✝ =
        Cell.type₂ f c

Tactic:
stdSimplex.mem_nonDegenerate_iff_mono,

Goal state after:
X : SSet
A : X.Subcomplex
P : A.Pairing
ι : Type v
inst✝¹ : LinearOrder ι
f : P.RankFunction ι
inst✝ : P.IsProper
j : ι
d : ℕ
x : f.Cell j
g : unop (op ⦋d⦌) ⟶ ⦋x.dim + 1⦌
hs✝ :
  (ConcreteCategory.hom (x.ιSigmaStdSimplex.app (op ⦋d⦌))) (stdSimplex.objEquiv.symm g) ∈
    (f.sigmaStdSimplex j).nonDegenerate d
hs : Mono (stdSimplex.objEquiv (stdSimplex.objEquiv.symm g))
hs'✝ :
  (ConcreteCategory.hom (x.ιSigmaStdSimplex.app (op ⦋d⦌))) (stdSimplex.objEquiv.symm g) ∉ (range (f.m j)).obj (op ⦋d⦌)
hs' : stdSimplex.objEquiv.symm g ∉ Λ[x.dim + 1, x.index].obj (op ⦋d⦌)
⊢ ∃ c,
    N.mk ((ConcreteCategory.hom (x.ιSigmaStdSimplex.app (op ⦋d⦌))) (stdSimplex.objEquiv.symm g)) hs✝ hs'✝ =
        Cell.type₁ f c ∨
      N.mk ((ConcreteCategory.hom (x.ιSigmaStdSimplex.app (op ⦋d⦌))) (stdSimplex.objEquiv.symm g)) hs✝ hs'✝ =
        Cell.type₂ f c