A surfer on a whiteboard catches a wave.
A woman is surfing.
Not all surfers are a woman.
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_catch(e1) & n_wave(x3) & on(x1,x2) & n_whiteboard(x2) & n_surfer(x1))
exists e1 x1.(Actor(e1,x1) & v_surf(e1) & n_woman(x1))