Goal:
  
  A : Type
  B : Type
  R : nat → A → B → Type
  l2 : list A
  r2 : list B
  n : nat
  h2 : All2i R (n + 0) l2 r2
  ============================
   (n = n + 0)


DEBUG:Going to execute:
intros; Zify.zify_pre_hook; zify_elim_let; zify_op