case inl
E : ℕ → Type u_1
x : (n : ℕ) → E n
n i : ℕ
hi : i ≤ n
h : dist x x < (1 / 2) ^ n
⊢ x i = x i

case inr
E : ℕ → Type u_1
x y : (n : ℕ) → E n
n : ℕ
h : dist x y < (1 / 2) ^ n
i : ℕ
hi : i ≤ n
hne : x ≠ y
⊢ x i = y i
E : ℕ → Type u_1
x y : (n : ℕ) → E n
n : ℕ
h : dist x y < (1 / 2) ^ n
i : ℕ
hi : i ≤ n
⊢ x i = y i
rcases eq_or_ne x y with (rfl | hne)
case inr
E : ℕ → Type u_1
x y : (n : ℕ) → E n
n : ℕ
h : dist x y < (1 / 2) ^ n
i : ℕ
hi : i ≤ n
hne : x ≠ y
this : n < firstDiff x y
⊢ x i = y i
case inr
E : ℕ → Type u_1
x y : (n : ℕ) → E n
n : ℕ
h : dist x y < (1 / 2) ^ n
i : ℕ
hi : i ≤ n
hne : x ≠ y
⊢ x i = y i
have : n < firstDiff x y := by
  simpa [dist_eq_of_ne hne, inv_lt_inv, pow_lt_pow_iff, one_lt_two] using h
no goals
case inr
E : ℕ → Type u_1
x y : (n : ℕ) → E n
n : ℕ
h : dist x y < (1 / 2) ^ n
i : ℕ
hi : i ≤ n
hne : x ≠ y
this : n < firstDiff x y
⊢ x i = y i
exact apply_eq_of_lt_firstDiff (hi.trans_lt this)
no goals
case inl
E : ℕ → Type u_1
x : (n : ℕ) → E n
n i : ℕ
hi : i ≤ n
h : dist x x < (1 / 2) ^ n
⊢ x i = x i
rfl
no goals
E : ℕ → Type u_1
x y : (n : ℕ) → E n
n : ℕ
h : dist x y < (1 / 2) ^ n
i : ℕ
hi : i ≤ n
hne : x ≠ y
⊢ n < firstDiff x y
simpa [dist_eq_of_ne hne, inv_lt_inv, pow_lt_pow_iff, one_lt_two] using h