A bird watches the waves crash over the rocks.
a cat watches the waves
A cat and bird are two different animals.
exists e1 x1 x2 x3 x4.(n_rock(x4) & n_crash(x2) & of(x2,x3) & n_wave(x3) & over(e1,x4) & Theme(e1,x2) & Actor(e1,x1) & v_watch(e1) & n_bird(x1))
exists e1 x1 x2.(n_wave(x2) & Theme(e1,x2) & Actor(e1,x1) & v_watch(e1) & n_cat(x1))