Section Aristotle.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

(* Specifications: *)
Lemma aristotle__greenberg : aristotle_s_axiom -> greenberg_s_axiom.
(** This proof is inspired by Several topics from geometry, by Franz Rothe *)
Lemma aristotle__obtuse_case_elimination :
aristotle_s_axiom ->
~ hypothesis_of_obtuse_saccheri_quadrilaterals.
Lemma aristotle__acute_or_right :
aristotle_s_axiom ->
hypothesis_of_acute_saccheri_quadrilaterals \/ hypothesis_of_right_saccheri_quadrilaterals.