Theorem: Profinite.NobelingProof.C0_projOrd
File: Mathlib/Topology/Category/Profinite/Nobeling.lean

Proof steps:
state_before: I : Type u
inst✝¹ : LinearOrder I
inst✝ : IsWellOrder I fun x x_1 => x < x_1
C : Set (I → Bool)
o : Ordinal.{u}
hC : IsClosed C
hsC : contained C (Order.succ o)
ho : o < Ordinal.type fun x x_1 => x < x_1
x : I → Bool
hx : x ∈ C0 C ho
⊢ Proj (fun x => ord I x < o) x = x
state_after: case h
I : Type u
inst✝¹ : LinearOrder I
inst✝ : IsWellOrder I fun x x_1 => x < x_1
C : Set (I → Bool)
o : Ordinal.{u}
hC : IsClosed C
hsC : contained C (Order.succ o)
ho : o < Ordinal.type fun x x_1 => x < x_1
x : I → Bool
hx : x ∈ C0 C ho
i : I
⊢ Proj (fun x => ord I x < o) x i = x i
tactic: ext i
state_before: case h
I : Type u
inst✝¹ : LinearOrder I
inst✝ : IsWellOrder I fun x x_1 => x < x_1
C : Set (I → Bool)
o : Ordinal.{u}
hC : IsClosed C
hsC : contained C (Order.succ o)
ho : o < Ordinal.type fun x x_1 => x < x_1
x : I → Bool
hx : x ∈ C0 C ho
i : I
⊢ Proj (fun x => ord I x < o) x i = x i
state_after: case h
I : Type u
inst✝¹ : LinearOrder I
inst✝ : IsWellOrder I fun x x_1 => x < x_1
C : Set (I → Bool)
o : Ordinal.{u}
hC : IsClosed C
hsC : contained C (Order.succ o)
ho : o < Ordinal.type fun x x_1 => x < x_1
x : I → Bool
hx : x ∈ C0 C ho
i : I
⊢ o ≤ ord I i → false = x i
tactic: simp only [Proj, Set.mem_setOf, ite_eq_left_iff, not_lt]
state_before: case h
I : Type u
inst✝¹ : LinearOrder I
inst✝ : IsWellOrder I fun x x_1 => x < x_1
C : Set (I → Bool)
o : Ordinal.{u}
hC : IsClosed C
hsC : contained C (Order.succ o)
ho : o < Ordinal.type fun x x_1 => x < x_1
x : I → Bool
hx : x ∈ C0 C ho
i : I
⊢ o ≤ ord I i → false = x i
state_after: case h
I : Type u
inst✝¹ : LinearOrder I
inst✝ : IsWellOrder I fun x x_1 => x < x_1
C : Set (I → Bool)
o : Ordinal.{u}
hC : IsClosed C
hsC : contained C (Order.succ o)
ho : o < Ordinal.type fun x x_1 => x < x_1
x : I → Bool
hx : x ∈ C0 C ho
i : I
hi : o ≤ ord I i
⊢ false = x i
tactic: intro hi
state_before: case h
I : Type u
inst✝¹ : LinearOrder I
inst✝ : IsWellOrder I fun x x_1 => x < x_1
C : Set (I → Bool)
o : Ordinal.{u}
hC : IsClosed C
hsC : contained C (Order.succ o)
ho : o < Ordinal.type fun x x_1 => x < x_1
x : I → Bool
hx : x ∈ C0 C ho
i : I
hi : o ≤ ord I i
⊢ false = x i
state_after: case h
I : Type u
inst✝¹ : LinearOrder I
inst✝ : IsWellOrder I fun x x_1 => x < x_1
C : Set (I → Bool)
o : Ordinal.{u}
hC : IsClosed C
hsC : contained C (Order.succ o)
ho : o < Ordinal.type fun x x_1 => x < x_1
x : I → Bool
hx : x ∈ C0 C ho
i : I
hi : o < ord I i ∨ o = ord I i
⊢ false = x i
tactic: rw [le_iff_lt_or_eq] at hi
state_before: case h
I : Type u
inst✝¹ : LinearOrder I
inst✝ : IsWellOrder I fun x x_1 => x < x_1
C : Set (I → Bool)
o : Ordinal.{u}
hC : IsClosed C
hsC : contained C (Order.succ o)
ho : o < Ordinal.type fun x x_1 => x < x_1
x : I → Bool
hx : x ∈ C0 C ho
i : I
hi : o < ord I i ∨ o = ord I i
⊢ false = x i
state_after: case h.inl
I : Type u
inst✝¹ : LinearOrder I
inst✝ : IsWellOrder I fun x x_1 => x < x_1
C : Set (I → Bool)
o : Ordinal.{u}
hC : IsClosed C
hsC : contained C (Order.succ o)
ho : o < Ordinal.type fun x x_1 => x < x_1
x : I → Bool
hx : x ∈ C0 C ho
i : I
hi : o < ord I i
⊢ false = x i

case h.inr
I : Type u
inst✝¹ : LinearOrder I
inst✝ : IsWellOrder I fun x x_1 => x < x_1
C : Set (I → Bool)
o : Ordinal.{u}
hC : IsClosed C
hsC : contained C (Order.succ o)
ho : o < Ordinal.type fun x x_1 => x < x_1
x : I → Bool
hx : x ∈ C0 C ho
i : I
hi : o = ord I i
⊢ false = x i
tactic: cases' hi with hi hi