lax_exact Int.natAbs_add_le₃ (f₁ (f₂ (x + y)) - f₁ (f₂ (x + y) - f₂ x - f₂ y) - f₁ (f₂ x + f₂ y))
                             (f₁ (f₂ (x + y) - f₂ x - f₂ y))
                             (f₁ (f₂ x + f₂ y) - f₁ (f₂ x) - f₁ (f₂ y))
G : Type u_1
inst✝ : AddCommGroup G
f₁ : ℤ → ℤ
bound₁ : ℕ
h₁ : AlmostAdditive f₁ bound₁
f₂ : G → ℤ
bound₂ : ℕ
h₂ : AlmostAdditive f₂ bound₂
x y : G
⊢ |f₁ (f₂ (x + y)) - f₁ (f₂ x) - f₁ (f₂ y)| ≤
    |f₁ (f₂ (x + y)) - f₁ (f₂ (x + y) - f₂ x - f₂ y) - f₁ (f₂ x + f₂ y)| + |f₁ (f₂ (x + y) - f₂ x - f₂ y)| +
      |f₁ (f₂ x + f₂ y) - f₁ (f₂ x) - f₁ (f₂ y)|
case e_a.e_m
G : Type u_1
inst✝ : AddCommGroup G
f₁ : ℤ → ℤ
bound₁ : ℕ
h₁ : AlmostAdditive f₁ bound₁
f₂ : G → ℤ
bound₂ : ℕ
h₂ : AlmostAdditive f₂ bound₂
x y : G
⊢ f₁ (f₂ (x + y)) - f₁ (f₂ x) - f₁ (f₂ y) =
    f₁ (f₂ (x + y)) - f₁ (f₂ (x + y) - f₂ x - f₂ y) - f₁ (f₂ x + f₂ y) + f₁ (f₂ (x + y) - f₂ x - f₂ y) +
      (f₁ (f₂ x + f₂ y) - f₁ (f₂ x) - f₁ (f₂ y))