Goal:
  
  A : Type
  p : nat → A → bool
  q : nat → A → bool
  l : list A
  l' : list A
  n : nat
  a : A
  l0 : list A
  IHl0 : ∀ (p : nat → A → bool) (n : nat),
           alli p n l0 = alli (λ i : nat, p (n + i)) 0 l0
  x : nat
  ============================
   (p (S n + x) =1 p (S (n + x)))


DEBUG:Going to execute:
solve
[ trivial
with eq_true
| reflexivity
| symmetry; trivial
| contradiction
| congruence ]