magical.lean:2:21-2:56: error: invalid projection, the expression
  Exists.intro 1 (Nat.le_refl 1)
is a proposition and has type
  ∃ x, x ≥ 1
but the projected value is not, it has type
  Nat
magical.lean:5:8-5:18: error: (kernel) invalid projection
  h.2