p.fst : ℕ
p.fst : ℕ
p.snd : ℕ
p.snd : ℕ
f (p.fst) : ℕ
p.fst + p.snd : ℕ
λ (c : car), (c.pos).x : car → ℕ
proj_notation.lean:29:19: error: invalid field notation, 'fst' is not a valid "field" because environment does not contain 'car.fst'
  c
which has type
  car
λ (c : car), ⁇ : car → ?M_1
proj_notation.lean:31:21: error: invalid projection, index must be greater than 0
λ (c : car), ⁇ : car → ?M_1
proj_notation.lean:33:19: error: invalid projection, structure has only 2 field(s)
  c
which has type
  car
λ (c : car), ⁇ : car → ?M_1
proj_notation.lean:35:19: error: invalid projection, structure expected
  n
has type
  ℕ
λ (n : ℕ), ⁇ : ℕ → ?M_1
p.fst : ℕ
p.snd : ℕ
λ (c : car), (c.pos).y : car → ℕ