A police officer with a red helmet on a motorcycle going down the street.
A police officer is on patrol.
Police officers are not always on patrol.
exists e1 s1 s2 x1 x2 x3 x4 x5 x6.(n_street(x6) & a_topic(x1) & with(x1,x3) & on(x3,x4) & a_down(s2) & Manner(e1,s2) & Theme(e1,x6) & Actor(e1,x5) & v_go(e1) & (x4 = x5) & n_motorcycle(x4) & n_helmet(x3) & a_red(s1) & Theme(s1,x3) & n_officer(x1) & of(x1,x2) & n_police(x2))
exists p1 x1 x2.(exists x3.(on(x1,x3) & n_patrol(x3)) & n_officer(x1) & of(x1,x2) & n_police(x2))