A man in a helmet is doing stunts on a bike.
The man always wears a helmet when doing stunts.
Although the man is wearing a helmet, it does not imply that he always wears a helmet.
exists e1 x1 x2 x3 x4.(on(e1,x4) & n_bike(x4) & Theme(e1,x3) & Actor(e1,x1) & v_do(e1) & n_stunt(x3) & in(x1,x2) & n_helmet(x2) & n_man(x1))
exists e2 e1 s1 x1 x2 x3.(n_man(x1) & when(e1,e2) & Theme(e2,x3) & Actor(e2,x1) & v_do(e2) & n_stunt(x3) & a_always(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_wear(e1) & n_helmet(x2))