(** * CFP to CFI *)
Section Palindrome.
Variable Sigma : list symbol.
Notation StartG := (fresh Sigma).
Definition palin_G : cfg :=
(StartG, (StartG, []) ::
flat_map (fun g => [ (StartG, [g]);  (StartG, [g; StartG; g]) ]) Sigma).

Lemma listI : forall (A : Type) (P : list A -> Prop), P [] -> (forall x, P [x]) -> (forall (x : A) (y : A) (l : list A), P l -> P (x :: l ++ [y])) -> forall l : list A, P l.