A father and son at a Walmart.
The father and son are at church.
The father and son cannot be at Walmart and church at the same time.
exists s1 x1 x2 x3.(a_topic(s1) & subset_of(x2,s1) & at(x2,x3) & ne_org_walmart(x3) & n_son(x2) & subset_of(x1,s1) & n_father(x1))
exists p1 x1 x2 x3.(n_son(x3) & n_father(x2) & subset_of(x3,x1) & subset_of(x2,x1) & exists x4.(at(x1,x4) & n_church(x4)))