A group of friends socializing at a barbecue.
People are eating hotdogs and burgers.
One can eat many things at a barbecue.  More than just hotdogs and burgers can be served at a barbecue.
exists e1 x1 x2 x3 x4.(a_topic(x1) & at(e1,x4) & n_barbecue(x4) & Actor(e1,x3) & v_socialize(e1) & (x1 = x3) & of(x1,x2) & n_friend(x2) & n_group(x1))
exists e1 x1 x2 x3 x4.(Theme(e1,x2) & Actor(e1,x1) & v_eat(e1) & subset_of(x4,x2) & n_burger(x4) & subset_of(x3,x2) & n_hotdog(x3) & n_people(x1))