Several kinds and adults sit on a porch at night
The people on the porch are engaged in a meaningless banter.
Just because the adults are sitting on a portch does not mean that they are engaged in meaningless banter or any banter.  They could be just sitting on the porch.
exists e1 s1 x1 x2 x3 x4 x5.(at(e1,x5) & n_night(x5) & on(e1,x4) & n_porch(x4) & Actor(e1,x1) & v_sit(e1) & subset_of(x3,x1) & n_adult(x3) & subset_of(x2,x1) & n_kind(x2) & a_several(s1) & Theme(s1,x2))
exists e1 s1 x1 x2 x3.(n_porch(x2) & n_people(x1) & in(e1,x3) & n_banter(x3) & a_meaningless(s1) & Theme(s1,x3) & Theme(e1,x1) & v_engage(e1) & on(x1,x2))