version 12 by Michael Callaghan
Section 1.8 - Define a value to determine if a Patroller is on the outward or inward journey for TwoWay and TwoWayRepeated Routes
RouteLeg is a kind of value. The RouteLegs are OutwardBound and InwardBound.
A Patroller has a RouteLeg. A Patroller is usually OutwardBound.