A man is riding a bicycle.
A man is training for a bike competition
A man riding a bicycle is not necessarily training for a bike competition.
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bicycle(x2) & n_man(x1))
exists e1 x1 x2 x3.(for(e1,x2) & n_competition(x2) & of(x2,x3) & n_bike(x3) & Actor(e1,x1) & v_train(e1) & n_man(x1))