SHOW_OPEN_EDGES is used to highlight open edges between faces of
imported face parts.
----(SHOW_OPEN_EDGES)----|SELECT S_PART|---->
This action has no options.
Use this action to highlight gaps between faces of an imported
face part.
SHOW_OPEN_EDGES [select face part to highlight]
CREATE_FACE terminate action
FLIP_FACES terminate action
GATHER_FACES terminate action
REINTERSECT_FACES terminate action