fact: Definition pres_bet_line {Tm: Tarski_neutral_dimensionless} (f : @Tpoint Tn -> @Tpoint Tm) P Q := forall A B C, Col P Q A -> Col P Q B -> Col P Q C -> Bet A B C -> Bet (f A) (f B) (f C).
imports: GeoCoq.Tarski_dev.Definitions