A geometric figure has bilateral symmetry if reflection in a line or plane maps it to itself. Bilateral symmetry is therefore another name for mirror symmetry. In the plane, the reflecting line is an axis of symmetry. In three dimensions, the reflecting plane is a plane of symmetry. For a planar graph embedding, bilateral symmetry means that reflection in some line maps the embedded graph to itself. An embedding specified by LCF notation is bilaterally symmetric when it satisfies this condition.
