A man is riding the bike without wearing his helmet.
A man is on a bike.
without wearing his helmet, he is riding a bike
exists e1 x1 x2 x3.(n_helmet(x3) & of(x3,x2) & n_male(x2) & n_bike(x2) & -exists e2.(manner(e1,e2) & Theme(e2,x3) & Actor(e2,x1) & v_wear(e2)) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_man(x1))
exists p1 x1.(exists x2.(on(x1,x2) & n_bike(x2)) & n_man(x1))