Goal:
  
  ============================
   (forall T : Type -> Type,
    Monad T ->
    forall (A : Type) (P : nat -> A -> Type) (Q : A -> Type),
    (forall (n : nat) (x : A), ∥ Q x ∥ -> T (∥ P n x ∥)) ->
    forall l0 : list A,
    nat ->
    forall (a : A) (l : list A), a :: l = l0 -> ∥ All Q (a :: l) ∥ -> ∥ Q a ∥)


DEBUG:Going to execute:
simpl; intros