For movement with the left hand, the Δ-shaped arrowhead is hollow (white); for movement with the right hand, it is solid (black). When both hands move as one, an open (Λ-shaped) arrowhead is used.
For movement with the left hand the Δ-shaped arrowhead is hollow (white); for movement with the right hand it is solid (black) When both hands move as one an open (Λ-shaped) arrowhead is used