A man in red pants walking on rocks.
The man is surfing.
A man surfing can not be walking on rocks.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & in(x1,x2) & on(e1,x4) & n_rock(x4) & Actor(e1,x3) & v_walk(e1) & (x2 = x3) & n_pants(x2) & a_red(s1) & Theme(s1,x2) & n_man(x1))
exists e1 x1.(n_man(x1) & Actor(e1,x1) & v_surf(e1))