A man riding a motorcycle while wearing a black uniform.
a woman rides a bike
It is either a man or a woman. They are either on a motorcycle or a bike.
exists e2 e1 s1 x1 x2 x3 x4.(a_topic(x1) & while(e1,e2) & Theme(e2,x4) & Actor(e2,x2) & v_wear(e2) & n_uniform(x4) & a_black(s1) & Theme(s1,x4) & Theme(e1,x3) & Actor(e1,x2) & v_ride(e1) & n_motorcycle(x3) & (x1 = x2) & n_man(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bike(x2) & n_woman(x1))