Section Suma_1.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.
(** Unicity of the sum. *)
(** Commutativity of the sum. *)
(** CongA preserves SumA. *)
(** Out preserves SumA. *)
(** ABC + 0 =  ABC (two lemmas) *)
(** 0 + DEF = DEF (two lemmas) *)
(** Some permutation properties:*)
(** Basic cases of sum *)
(** Characterization of SAMS using LeA. *)

Lemma conga2_sams__sams : forall A B C D E F A' B' C' D' E' F',
CongA A B C A' B' C' -> CongA D E F D' E' F' ->
SAMS A B C D E F -> SAMS A' B' C' D' E' F'.