Goal:
  
  A : Type
  B : Type
  R : nat → A → B → Type
  n : nat
  l0 : list A
  l : list B
  a : All2i R n l0 l
  ============================
   (noConfusionHom_All2i_obligation_1 A B R n l0 l a a
      (noConfusionHom_All2i_obligation_2 A B R n l0 l a a eq_refl) = eq_refl)


DEBUG:Going to execute:
try intros until H; intro_block_id H || intro_block H
Level 4: evaluation returns
try intros until H; intro_block_id H || intro_block H;
 (try simpl in H; DepElim.simplify_equations_in H)
where
H := a
of type
constr of type tacvalue