∀ {α : Type u} {β : α → Type v} {x : BEq α} {x_1 : Hashable α} {m₁ m₂ : Std.DHashMap α β} [inst : LawfulBEq α]
  [inst_1 : (k : α) → BEq (β k)] [∀ (k : α), LawfulBEq (β k)], (m₁ == m₂) = true → m₁.Equiv m₂