Two children and their parents are on the floor opening presents.
Two children are chained up by their parents in a basement.
The children cannot be opening presents if they are chained up.
exists p1 x1 x2 x3 x4 x5 x6.(n_present(x4) & of(x4,x6) & n_opening(x6) & of(x4,x5) & n_floor(x5) & on(x1,x4) & subset_of(x3,x1) & n_parent(x3) & of(x3,x2) & n_thing(x2) & subset_of(x2,x1) & n_child(x2) & card_eq_2(x2))
exists e1 s1 x1 x2 x3.(Actor(e1,x2) & in(x2,x3) & n_basement(x3) & n_parent(x2) & of(x2,x1) & n_thing(x1) & a_up(s1) & Manner(e1,s1) & Theme(e1,x1) & v_chain(e1) & n_child(x1) & card_eq_2(x1))