Theorem: CategoryTheory.Limits.WidePullback.hom_ext
File: Mathlib/CategoryTheory/Limits/Shapes/WidePullbacks.lean

Proof steps:
state_before: J : Type w
C✝ : Type u
inst✝² : Category.{v, u} C✝
C : Type u
inst✝¹ : Category.{v, u} C
B : C
objs : J → C
arrows : (j : J) → objs j ⟶ B
inst✝ : HasWidePullback B objs arrows
X : C
f : X ⟶ B
fs : (j : J) → X ⟶ objs j
w : ∀ (j : J), fs j ≫ arrows j = f
g1 g2 : X ⟶ widePullback B objs arrows
⊢ (∀ (j : J), g1 ≫ π arrows j = g2 ≫ π arrows j) → g1 ≫ base arrows = g2 ≫ base arrows → g1 = g2
state_after: J : Type w
C✝ : Type u
inst✝² : Category.{v, u} C✝
C : Type u
inst✝¹ : Category.{v, u} C
B : C
objs : J → C
arrows : (j : J) → objs j ⟶ B
inst✝ : HasWidePullback B objs arrows
X : C
f : X ⟶ B
fs : (j : J) → X ⟶ objs j
w : ∀ (j : J), fs j ≫ arrows j = f
g1 g2 : X ⟶ widePullback B objs arrows
h1 : ∀ (j : J), g1 ≫ π arrows j = g2 ≫ π arrows j
h2 : g1 ≫ base arrows = g2 ≫ base arrows
⊢ g1 = g2
tactic: intro h1 h2
state_before: J : Type w
C✝ : Type u
inst✝² : Category.{v, u} C✝
C : Type u
inst✝¹ : Category.{v, u} C
B : C
objs : J → C
arrows : (j : J) → objs j ⟶ B
inst✝ : HasWidePullback B objs arrows
X : C
f : X ⟶ B
fs : (j : J) → X ⟶ objs j
w : ∀ (j : J), fs j ≫ arrows j = f
g1 g2 : X ⟶ widePullback B objs arrows
h1 : ∀ (j : J), g1 ≫ π arrows j = g2 ≫ π arrows j
h2 : g1 ≫ base arrows = g2 ≫ base arrows
⊢ g1 = g2
state_after: case w
J : Type w
C✝ : Type u
inst✝² : Category.{v, u} C✝
C : Type u
inst✝¹ : Category.{v, u} C
B : C
objs : J → C
arrows : (j : J) → objs j ⟶ B
inst✝ : HasWidePullback B objs arrows
X : C
f : X ⟶ B
fs : (j : J) → X ⟶ objs j
w : ∀ (j : J), fs j ≫ arrows j = f
g1 g2 : X ⟶ widePullback B objs arrows
h1 : ∀ (j : J), g1 ≫ π arrows j = g2 ≫ π arrows j
h2 : g1 ≫ base arrows = g2 ≫ base arrows
⊢ ∀ (j : WidePullbackShape J),
    g1 ≫ limit.π (WidePullbackShape.wideCospan B objs arrows) j =
      g2 ≫ limit.π (WidePullbackShape.wideCospan B objs arrows) j
tactic: apply limit.hom_ext
state_before: case w
J : Type w
C✝ : Type u
inst✝² : Category.{v, u} C✝
C : Type u
inst✝¹ : Category.{v, u} C
B : C
objs : J → C
arrows : (j : J) → objs j ⟶ B
inst✝ : HasWidePullback B objs arrows
X : C
f : X ⟶ B
fs : (j : J) → X ⟶ objs j
w : ∀ (j : J), fs j ≫ arrows j = f
g1 g2 : X ⟶ widePullback B objs arrows
h1 : ∀ (j : J), g1 ≫ π arrows j = g2 ≫ π arrows j
h2 : g1 ≫ base arrows = g2 ≫ base arrows
⊢ ∀ (j : WidePullbackShape J),
    g1 ≫ limit.π (WidePullbackShape.wideCospan B objs arrows) j =
      g2 ≫ limit.π (WidePullbackShape.wideCospan B objs arrows) j
state_after: case w.none
J : Type w
C✝ : Type u
inst✝² : Category.{v, u} C✝
C : Type u
inst✝¹ : Category.{v, u} C
B : C
objs : J → C
arrows : (j : J) → objs j ⟶ B
inst✝ : HasWidePullback B objs arrows
X : C
f : X ⟶ B
fs : (j : J) → X ⟶ objs j
w : ∀ (j : J), fs j ≫ arrows j = f
g1 g2 : X ⟶ widePullback B objs arrows
h1 : ∀ (j : J), g1 ≫ π arrows j = g2 ≫ π arrows j
h2 : g1 ≫ base arrows = g2 ≫ base arrows
⊢ g1 ≫ limit.π (WidePullbackShape.wideCospan B objs arrows) none =
    g2 ≫ limit.π (WidePullbackShape.wideCospan B objs arrows) none

case w.some
J : Type w
C✝ : Type u
inst✝² : Category.{v, u} C✝
C : Type u
inst✝¹ : Category.{v, u} C
B : C
objs : J → C
arrows : (j : J) → objs j ⟶ B
inst✝ : HasWidePullback B objs arrows
X : C
f : X ⟶ B
fs : (j : J) → X ⟶ objs j
w : ∀ (j : J), fs j ≫ arrows j = f
g1 g2 : X ⟶ widePullback B objs arrows
h1 : ∀ (j : J), g1 ≫ π arrows j = g2 ≫ π arrows j
h2 : g1 ≫ base arrows = g2 ≫ base arrows
val✝ : J
⊢ g1 ≫ limit.π (WidePullbackShape.wideCospan B objs arrows) (some val✝) =
    g2 ≫ limit.π (WidePullbackShape.wideCospan B objs arrows) (some val✝)
tactic: rintro (_ | _)