A tan dog runs through the brush.
A cat is sleeping on a sunny windowsill.
It must be either a dog or a cat. One cannot run and be sleeping at the same time.
exists e1 s1 x1 x2.(n_brush(x2) & through(e1,x2) & Actor(e1,x1) & v_run(e1) & n_dog(x1) & a_tan(s1) & Theme(s1,x1))
exists e1 s1 x1 x2.(on(e1,x2) & n_windowsill(x2) & a_sunny(s1) & Theme(s1,x2) & Actor(e1,x1) & v_sleep(e1) & n_cat(x1))