Module: Mathlib.AlgebraicGeometry.Cover.Directed

Goal state before:
pp: case refine_1
P : MorphismProperty Scheme
X : Scheme
𝒰 : X.OpenCover
inst✝ : Preorder 𝒰.I₀
hle : ∀ {i j : 𝒰.I₀}, i ≤ j ↔ Hom.opensRange (𝒰.f i) ≤ Hom.opensRange (𝒰.f j)
H : TopologicalSpace.Opens.IsBasis (Set.range fun i ↦ Hom.opensRange (𝒰.f i))
i j : 𝒰.I₀
x : ↥(pullback (𝒰.f i) (𝒰.f j))
this : (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i) x ∈ Hom.opensRange (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i)
k : 𝒰.I₀
h : (fun i ↦ Hom.opensRange (𝒰.f i)) k ≤ Hom.opensRange (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i)
y : ↥(𝒰.X k)
hy : (𝒰.f k) y = (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i) x
⊢ Hom.opensRange (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i) ≤ Hom.opensRange (𝒰.f i)

pp: case refine_2
P : MorphismProperty Scheme
X : Scheme
𝒰 : X.OpenCover
inst✝ : Preorder 𝒰.I₀
hle : ∀ {i j : 𝒰.I₀}, i ≤ j ↔ Hom.opensRange (𝒰.f i) ≤ Hom.opensRange (𝒰.f j)
H : TopologicalSpace.Opens.IsBasis (Set.range fun i ↦ Hom.opensRange (𝒰.f i))
i j : 𝒰.I₀
x : ↥(pullback (𝒰.f i) (𝒰.f j))
this : (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i) x ∈ Hom.opensRange (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i)
k : 𝒰.I₀
h : (fun i ↦ Hom.opensRange (𝒰.f i)) k ≤ Hom.opensRange (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i)
y : ↥(𝒰.X k)
hy : (𝒰.f k) y = (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i) x
⊢ Hom.opensRange (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i) ≤ Hom.opensRange (𝒰.f j)

pp: case refine_3
P : MorphismProperty Scheme
X : Scheme
𝒰 : X.OpenCover
inst✝ : Preorder 𝒰.I₀
hle : ∀ {i j : 𝒰.I₀}, i ≤ j ↔ Hom.opensRange (𝒰.f i) ≤ Hom.opensRange (𝒰.f j)
H : TopologicalSpace.Opens.IsBasis (Set.range fun i ↦ Hom.opensRange (𝒰.f i))
i j : 𝒰.I₀
x : ↥(pullback (𝒰.f i) (𝒰.f j))
this : (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i) x ∈ Hom.opensRange (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i)
k : 𝒰.I₀
h : (fun i ↦ Hom.opensRange (𝒰.f i)) k ≤ Hom.opensRange (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i)
y : ↥(𝒰.X k)
hy : (𝒰.f k) y = (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i) x
⊢ (pullback.lift (IsOpenImmersion.lift (𝒰.f i) (𝒰.f k) ⋯) (IsOpenImmersion.lift (𝒰.f j) (𝒰.f k) ⋯) ⋯) y = x

Tactic:
· rw [Scheme.Hom.opensRange_comp]
      exact Set.image_subset_range _ _

Goal state after:
case refine_2
P : MorphismProperty Scheme
X : Scheme
𝒰 : X.OpenCover
inst✝ : Preorder 𝒰.I₀
hle : ∀ {i j : 𝒰.I₀}, i ≤ j ↔ Hom.opensRange (𝒰.f i) ≤ Hom.opensRange (𝒰.f j)
H : TopologicalSpace.Opens.IsBasis (Set.range fun i ↦ Hom.opensRange (𝒰.f i))
i j : 𝒰.I₀
x : ↥(pullback (𝒰.f i) (𝒰.f j))
this : (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i) x ∈ Hom.opensRange (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i)
k : 𝒰.I₀
h : (fun i ↦ Hom.opensRange (𝒰.f i)) k ≤ Hom.opensRange (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i)
y : ↥(𝒰.X k)
hy : (𝒰.f k) y = (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i) x
⊢ Hom.opensRange (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i) ≤ Hom.opensRange (𝒰.f j)

case refine_3
P : MorphismProperty Scheme
X : Scheme
𝒰 : X.OpenCover
inst✝ : Preorder 𝒰.I₀
hle : ∀ {i j : 𝒰.I₀}, i ≤ j ↔ Hom.opensRange (𝒰.f i) ≤ Hom.opensRange (𝒰.f j)
H : TopologicalSpace.Opens.IsBasis (Set.range fun i ↦ Hom.opensRange (𝒰.f i))
i j : 𝒰.I₀
x : ↥(pullback (𝒰.f i) (𝒰.f j))
this : (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i) x ∈ Hom.opensRange (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i)
k : 𝒰.I₀
h : (fun i ↦ Hom.opensRange (𝒰.f i)) k ≤ Hom.opensRange (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i)
y : ↥(𝒰.X k)
hy : (𝒰.f k) y = (pullback.fst (𝒰.f i) (𝒰.f j) ≫ 𝒰.f i) x
⊢ (pullback.lift (IsOpenImmersion.lift (𝒰.f i) (𝒰.f k) ⋯) (IsOpenImmersion.lift (𝒰.f j) (𝒰.f k) ⋯) ⋯) y = x