cases y
case mk
C : Container
R : M C → M C → Prop
h₀ :
  ∀ (x y : M C),
    R x y →
      ∃ node k₁ k₂,
        destruct x = { fst := node, snd := k₁ } ∧
          destruct y = { fst := node, snd := k₂ } ∧ ∀ (i : B C node), R (k₁ i) (k₂ i)
y : M C
approx✝ : (n : Nat) → Approx C n
agrees✝ : ∀ (n : Nat), Agree (approx✝ n) (approx✝ (Nat.succ n))
h₁ : R { approx := approx✝, agrees := agrees✝ } y
h₂ : { approx := approx✝, agrees := agrees✝ }.approx = y.approx
⊢ { approx := approx✝, agrees := agrees✝ } = y
case mk.mk
C : Container
R : M C → M C → Prop
h₀ :
  ∀ (x y : M C),
    R x y →
      ∃ node k₁ k₂,
        destruct x = { fst := node, snd := k₁ } ∧
          destruct y = { fst := node, snd := k₂ } ∧ ∀ (i : B C node), R (k₁ i) (k₂ i)
approx✝¹ : (n : Nat) → Approx C n
agrees✝¹ : ∀ (n : Nat), Agree (approx✝¹ n) (approx✝¹ (Nat.succ n))
approx✝ : (n : Nat) → Approx C n
agrees✝ : ∀ (n : Nat), Agree (approx✝ n) (approx✝ (Nat.succ n))
h₁ : R { approx := approx✝¹, agrees := agrees✝¹ } { approx := approx✝, agrees := agrees✝ }
h₂ : { approx := approx✝¹, agrees := agrees✝¹ }.approx = { approx := approx✝, agrees := agrees✝ }.approx
⊢ { approx := approx✝¹, agrees := agrees✝¹ } = { approx := approx✝, agrees := agrees✝ }