A man and two children help put groceries on the check-out conveyor belt.
The man and children bought cereal.
The fact that the man and two children help put groceries on a check out-conveyor belt does not mean they necessarily bought the groceries. Not all groceries are cereal.
exists e1 p1 s1 x1 x2 x4 x5.(n_belt(x4) & of(x4,x5) & n_conveyor(x5) & a_check-out(s1) & Theme(s1,x4) & exists e2 x3.(on(e2,x4) & Theme(e2,x3) & Actor(e2,x1) & v_put(e2) & n_grocery(x3)) & Topic(e1,p1) & Actor(e1,x1) & v_help(e1) & n_child(x1) & card_eq_2(x1) & of(x1,x2) & n_man(x2))
exists e1 x1 x2 x3 x4.(n_child(x3) & n_man(x2) & subset_of(x3,x1) & subset_of(x2,x1) & Theme(e1,x4) & Actor(e1,x1) & v_buy(e1) & n_cereal(x4))