Section Suma_2.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.
(** ABC <= ABC + DEF. *)
(** DEF <= ABC + DEF. *)
(** LeA preserves SAMS. *)
(** SumA preserves LeA. *)
(** Unicity of the difference of angles. *)
(** Unicity of the difference on the left. *)
(** Associativity of the sum of angles. *)

Lemma conga_sams_nos__nts : forall A B C D E F J,
SAMS A B C D E F -> CongA C B J D E F -> ~ OS B C A J -> ~ TS A B C J.