Set: pp::colors
  Set: pp::unicode
let a : ℕ := 10, b : ℕ := 20, c : ℕ := 30, d : ℕ := 10 in a + b + c + d
let a : ℕ := 1000000000000000000,
    b : ℕ := 20000000000000000000,
    c : ℕ := 3000000000000000000,
    d : ℕ := 4000000000000000000
in a + b + c + d
let a : ℕ := 10 in a + 1 : ℕ
30
30
let a : ℤ := 20 in a + 10 : ℤ
  Set: lean::pp::coercion
let a : ℤ := nat_to_int 20 in a + (nat_to_int 10)