A man in a black singlet is on the back of another man in a wrestling match.
Nobody is wrestling
both wrestling it doesn't matter the details but in sentence 1 a man is and in sentence 2 nobody is
exists p1 s1 x1 x2 x3.(n_back(x3) & exists x4 x5 x6.(on(x1,x3) & of(x3,x4) & in(x4,x5) & n_match(x5) & of(x5,x6) & n_wrestling(x6) & n_man(x4) & -(x4 = x1)) & n_man(x1) & n_man(x1) & in(x1,x2) & n_singlet(x2) & a_black(s1) & Theme(s1,x2))
-exists e1 x1.(Actor(e1,x1) & v_wrestle(e1) & n_person(x1))