Goal:
  
  ============================
   (∀ (A B C : Type) (R : A → B → C → Type) (l0 : list A) 
      (l1 : list B) (l : list C) (a b : All3 R l0 l1 l) 
      (e : NoConfusionHom_All3 A B C R l0 l1 l a b),
      noConfusionHom_All3_obligation_2 A B C R l0 l1 l a b
        (noConfusionHom_All3_obligation_1 A B C R l0 l1 l a b e) = e)


DEBUG:Going to execute:
intros