Two emergency responders are at the scene of an incident.
The emergency responders are not at the incident.
They are either at the scene, or not at the scene.
exists p1 x1 x2 x3.(n_scene(x3) & exists x4.(at(x1,x3) & of(x3,x4) & n_incident(x4)) & n_responder(x1) & of(x1,x2) & n_emergency(x2) & card_eq_2(x1))
exists x1 x2 x3.(n_incident(x3) & n_responder(x1) & of(x1,x2) & n_emergency(x2) & -exists p1.at(x1,x3))