Goal:
  
  A : Type
  B : Type
  C : Type
  R : A → B → C → Type
  H : apply_noConfusion [] []
        (λ _ : True,
           DepElim.eq_simplification_sigma1 [] [] [] []
             (apply_noConfusion [] []
                (λ _ : True, apply_noConfusion [] [] (λ _ : True, True))))
        eq_refl eq_refl
  ============================
   (All3_nil = All3_nil)


DEBUG:Going to execute:
tac H