Orbital Movement Sequence

An orbital movement sequence records the direction of movement around a center as prograde (p) or retrograde (r). Prograde is established by the initial orbital direction, with retrograde indicating the opposite direction. Because chiral reflections are equivalent, these relative terms allow orbital movement to be represented without relying on clockwise/counterclockwise or right/left orientation.

In polycentric path systems, orbital direction may be considered at both global and local scales. Global orbital direction is established by the initial orbital direction in the primary (initial) subsystem and provides a common reference across the path system. Local orbital direction is established by the initial orbital direction within each subsystem and is interpreted relative to that subsystem’s center.