let s : foo :=
      {x := let v1 : ℕ := 10 + 10 + 20 + 30 + 40 + 10 + 20 + 30 + 40 + 50 + 10 + 10,
                v2 : ℕ := 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 20,
                v3 : ℕ := 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 20,
                v4 : ℕ := 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 20
            in v1 + v2 + v3 + v4,
       y := 20,
       z := tt}
in s.x + s.y :
  ℕ
let s : foo :=
      {foo .
       x := let v1 : ℕ := 10 + 10 + 20 + 30 + 40 + 10 + 20 + 30 + 40 + 50 + 10 + 10,
                v2 : ℕ := 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 20,
                v3 : ℕ := 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 20,
                v4 : ℕ := 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 20
            in v1 + v2 + v3 + v4,
       y := 20,
       z := tt}
in s.x + s.y :
  ℕ
foo.mk 10 20 ff : foo
{foo . x := 10, y := 20, z := ff} : foo
{x := 10, y := 20, z := ff} : foo
{x := 10, y := 20, z := ff}.x : ℕ
(1, 2).fst : ℕ
(boo 1 1).fst : ℕ
(h 0).fn 10 20 : ℕ