Man rollerskating in park.
The man is ice skating.
The man is either rollerskating or ice skating.
exists x1 x2 x3.(a_topic(x1) & in(x1,x3) & n_park(x3) & n_rollerskating(x1) & of(x1,x2) & n_man(x2))
exists p1 x1.(n_man(x1) & exists x2 x3.((x1 = x2) & n_skating(x2) & of(x2,x3) & n_ice(x3)))