Goal:
  
  A : Type
  p : nat → A → bool
  q : nat → A → bool
  l : list A
  l' : list A
  B : Type
  f : B → A
  n : nat
  a : B
  bs : list B
  IHbs : ∀ n : nat,
           alli p n (map f bs) = alli (λ (i : nat) (x : B), p i (f x)) n bs
  ============================
   (p n (f a) && alli (λ (i : nat) (x : B), p i (f x)) (S n) bs =
    p n (f a) && alli (λ (i : nat) (x : B), p i (f x)) (S n) bs)


DEBUG:Going to execute:
let rec do_ccl :=
            try do_atom; repeat (do_intro; try do_atom); try arith_congr;
             (solve [ split; do_ccl ])
           in
           (solve [ do_atom | use_hyps; do_ccl ]) ||
             fail "Cannot solve this goal"