Hint Immediate col_trivial_1 col_trivial_2 col_trivial_3: col.
Section T4_4.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma l4_16 : forall A B C D A' B' C' D',
FSC A B C D A' B' C' D' -> A<>B -> Cong C D C' D'.