Four men are rollerskating in a line, with the last three holding onto the hips of the man ahead of them.
People skating.
Four men are people and when they are roller-skating, they are skating.
exists e1 e2 s1 x1 x2 x3 x4.(n_hip(x3) & onto(e2,x3) & of(x3,x1) & of(x4,x1) & n_thing(x1) & ahead(x1,x4) & n_thing(x4) & n_man(x1) & n_man(x1) & Actor(e2,x1) & v_hold(e2) & with(e1,x1) & card_eq_3(x1) & a_last(s1) & Theme(s1,x1) & in(e1,x2) & n_line(x2) & Actor(e1,x1) & v_rollerskate(e1) & card_eq_4(x1))
exists e1 x1 x2.(a_topic(x1) & Actor(e1,x2) & v_skate(e1) & (x1 = x2) & n_people(x1))