A few guys outside grilling some food at night.
A few guys outside drinking bears and grilling some burgers for a barbeque.
Guys can grill without drinking beers.  A guy can grill other things besides burgers.  Grilling food at night does not indicate there is a barbeque.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & outside(x1,e1) & at(e1,x4) & n_night(x4) & Theme(e1,x3) & Actor(e1,x2) & v_grill(e1) & n_food(x3) & n_thing(x2) & n_guy(x1) & a_few(s1) & Theme(s1,x1))
exists e1 s1 s2 x1 x2 x3 x4 x5 x6.(a_topic(s1) & subset_of(e1,s1) & for(e1,x6) & n_barbeque(x6) & Theme(e1,x5) & Actor(e1,x4) & v_grill(e1) & n_burger(x5) & n_thing(x4) & subset_of(x1,s1) & outside(x1,x2) & n_bear(x2) & of(x2,x3) & n_drinking(x3) & n_guy(x1) & a_few(s2) & Theme(s2,x1))