Three men are working on a roof.
A man in cutting the grass
Three men are not a man.
exists e1 x1 x2.(on(e1,x2) & n_roof(x2) & Actor(e1,x1) & v_work(e1) & n_man(x1) & card_eq_3(x1))
exists e1 x1 x2 x3.(n_grass(x3) & a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_cut(e1) & (x1 = x2) & n_man(x1))