fact: Definition eqo := fun A B P A1 B1 P1 => ~Col A B P /\ ~Col A1 B1 P1 /\ forall C C1 B2 M B' C' K, Perp A B C A -> Per P C A -> Perp A1 B1 C1 A1 -> Per P1 C1 A1 -> Out A1 B1 B2 -> Cong A B A1 B2 -> Midpoint M A A1 -> Midpoint M B2 B' -> Midpoint M C1 C' -> Midpoint K B B' -> Bet C A C' \/ OS A K C C'.
imports: GeoCoq.Tarski_dev.Ch12_parallel_inter_dec