Section T10.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.
Goal forall A B C D, ~ Coplanar D C B A -> ~ Coplanar A B C D.

Lemma is_image_spec_dec :
forall A B C D, ReflectL A B C D \/ ~ ReflectL A B C D.