a lone four wheeler wearing a helmet riding along a dusty path.
There is more than one person on the four wheeler
One does not know if there is more than one person on the four wheeler, especially since it says "a lone four wheeler"
exists e1 s1 s2 s3 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & along(x3,x4) & n_path(x4) & a_dusty(s3) & Theme(s3,x4) & n_riding(x3) & a_helmet(s2) & Theme(s2,x3) & (x1 = x2) & n_wheeler(x1) & card_eq_4(x1) & a_lone(s1) & Theme(s1,x1))
exists p1 x1 x4.(n_wheeler(x4) & card_eq_4(x4) & exists s1 x2 x3.((x1 = x2) & on(x2,x4) & than(s1,x3) & card_eq_1(x3) & Theme(s1,x2) & a_more(s1) & n_person(x2)))