A man is riding a red windsurfer.
A woman is riding a red windsurfer.
One cannot be a man and woman at the same time.
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_windsurfer(x2) & a_red(s1) & Theme(s1,x2) & n_man(x1))
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_windsurfer(x2) & a_red(s1) & Theme(s1,x2) & n_woman(x1))