p^.fst : ℕ
p^.fst : ℕ
p^.snd : ℕ
p^.snd : ℕ
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:34:19: error: invalid '^.' notation, 'fst' is not a valid "field" because environment does not contain 'car.fst'
  c
which has type
  car
proj_notation.lean:36:20: error: invalid projection, index must be greater than 0
proj_notation.lean:38:19: error: invalid projection, structure has only 2 field(s)
  c
which has type
  car
proj_notation.lean:40:19: error: invalid projection, structure expected
  n
has type
  ℕ
p^.fst : ℕ
p^.snd : ℕ
λ (c : car), (c^.pos)^.y : car → ℕ