A surfer is riding a very big wave.
The surfer is in the ocean waiting for a wave.
Riding a wave is very different from waiting for one.
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_wave(x2) & a_big(s1) & Theme(s1,x2) & r_very(x2) & n_surfer(x1))
exists p1 x1 x2.(n_ocean(x2) & n_surfer(x1) & exists e1 x3 x4.(in(x1,x2) & for(e1,x4) & n_wave(x4) & Actor(e1,x3) & v_wait(e1) & (x2 = x3)))