the boy laying face down on a skateboard is being pushed along the ground by another boy.
Two brothers are outside.
The boys could be unrelated, they may not be brothers.
exists e2 e1 x1 x2 x3 x4 x5 x6.(n_boy(x1) & n_boy(x1) & n_ground(x5) & Actor(e2,x6) & n_boy(x6) & -(x6 = x1) & along(e2,x5) & Theme(e2,x1) & v_push(e2) & on(e1,x4) & n_skateboard(x4) & r_down(e1) & Theme(e1,x3) & Actor(e1,x2) & v_lay(e1) & n_face(x3) & (x1 = x2))
exists s1 x1.(Theme(s1,x1) & a_outside(s1) & n_brother(x1) & card_eq_2(x1))