(** The sum of two supplementary angles is a flat angle (two lemmas) *)

(* Specifications: *)
Lemma suma_suppa__bet : forall A B C D E F G H I,
SuppA A B C D E F -> SumA A B C D E F G H I -> Bet G H I.
Lemma bet_suppa__suma : forall A B C D E F G H I, G <> H -> H <> I ->
SuppA A B C D E F -> Bet G H I -> SumA A B C D E F G H I.