proposition: Lemma Forall_of_count_eq_length : forall P l, count P l = length l -> Forall P l.
proof: Proof. Proof using. introv. rewrite~ Forall_eq_count_eq_length. Qed.
imports: TLC(LibTactics LibLogic LibOperation LibReflect LibProd LibNat LibInt LibOption LibWf) TLC(LibInt)