Goal:
  
  A : Type
  P : A → A → Type
  Q : A → Type
  R : A → Type
  l : list A
  l' : list A
  ============================
   (All Q l
    → All R l' → OnOne2 P l l' → OnOne2 (λ x y : A, P x y × Q x × R y) l l')


DEBUG:Going to execute:
intros H H'; induction 1; constructor; try inv H; try inv H'