a family walking down the street
The mother and father watch the children walking.
Not a families consist of a mother and a father.
exists x1 x2 x3.(n_street(x3) & a_topic(x1) & down(x1,x3) & n_walk(x1) & of(x1,x2) & n_family(x2))
exists e1 x1 x2 x3 x4 x5.(n_walking(x4) & of(x4,x5) & n_child(x5) & n_father(x3) & n_mother(x2) & subset_of(x3,x1) & subset_of(x2,x1) & Theme(e1,x4) & Actor(e1,x1) & v_watch(e1))