A cyclist is riding a bicycle on a curved road up a hill.
A man changes his bicycle chain.
One cannot ride a bicycle and change the bicycle chain simultaneously.
exists e1 s1 x1 x2 x3 x4.(up(e1,x4) & n_hill(x4) & on(e1,x3) & n_road(x3) & a_curved(s1) & Theme(s1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bicycle(x2) & n_cyclist(x1))
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_change(e1) & n_chain(x2) & of(x2,x3) & n_bicycle(x3) & of(x2,x1) & n_male(x1) & n_man(x1))