A man balancing on one hand on a mat.
Nobody is balancing
A man is not nobody.
exists e1 x1 x2 x3 x4.(a_topic(x1) & on(e1,x3) & on(x3,x4) & n_mat(x4) & n_hand(x3) & card_eq_1(x3) & Actor(e1,x2) & v_balance(e1) & (x1 = x2) & n_man(x1))
-exists e1 x1.(Actor(e1,x1) & v_balance(e1) & n_person(x1))