Goal:
  
  A : Type
  B : Type
  C : Type
  R : A → B → C → Type
  l0 : list A
  l1 : list B
  l : list C
  ============================
   (∀ a : All3 R l0 l1 l,
      let H := CoreTactics.block in
      let H0 := CoreTactics.block in
      noConfusionHom_All3_obligation_1 A B C R l0 l1 l a a
        (noConfusionHom_All3_obligation_2 A B C R l0 l1 l a a eq_refl) =
      eq_refl)


DEBUG:Going to execute:
intros p