Two boys waterskiing.
cat sits on table
One cannot be waterskiing and sitting on a table
exists e1 x1.(Actor(e1,x1) & v_waterskie(e1) & n_boy(x1) & card_eq_2(x1))
exists e1 x1 x2.(on(e1,x2) & n_table(x2) & Actor(e1,x1) & v_sit(e1) & n_cat(x1))