A man performing on a guitar.
A man is at a pond fishing.
A man fishing at a pond cannot also be preforming on a guitar.
exists e1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_guitar(x3) & Actor(e1,x2) & v_perform(e1) & (x1 = x2) & n_man(x1))
exists p1 x1.(exists s1 x2.(at(x1,x2) & n_fishing(x2) & a_pond(s1) & Theme(s1,x2)) & n_man(x1))