match n with 
| 0 => 
  have meq0 : m = 0 := Nat.eq_zero_of_le_zero h
  rw [meq0]
  simp
| n'+1 => 
  simp [plus]
  calc 
    m ≤ n'+1 := by exact h 
    _ ≤ (n'+1)+1 := by exact Nat.le_succ _
α β γ δ : Type
f : α → β
g : β → γ
h✝ : γ → δ
m n : ℕ
h : m ≤ n
⊢ m ≤ plus n 1
no goals