A man without a helmet is riding a red bike.
The man is riding a bike.
a man is riding a bike without helmet
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bike(x2) & a_red(s1) & Theme(s1,x2) & -exists x3.(with(x1,x3) & n_helmet(x3)) & n_man(x1))
exists e1 x1 x2.(n_man(x1) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bike(x2))