A father and son working on a boat.
dad and son repairing a boat
The father and son are repairing a boat.
exists e1 s1 x1 x2 x3 x4.(a_topic(s1) & subset_of(x2,s1) & on(e1,x4) & n_boat(x4) & Actor(e1,x3) & v_work(e1) & (x2 = x3) & n_son(x2) & subset_of(x1,s1) & n_father(x1))
exists e1 s1 x1 x2 x3 x4.(a_topic(s1) & subset_of(x2,s1) & Theme(e1,x4) & Actor(e1,x3) & v_repair(e1) & n_boat(x4) & (x2 = x3) & n_son(x2) & subset_of(x1,s1) & n_dad(x1))