A woman and a girl are sitting under a tree.
A woman and a girl are standing by a tree.
One can't be sitting if they are standing.
exists e1 x1 x2 x3 x4.(under(e1,x4) & n_tree(x4) & Actor(e1,x1) & v_sit(e1) & subset_of(x3,x1) & n_girl(x3) & subset_of(x2,x1) & n_woman(x2))
exists e1 x1 x2 x3 x4.(by(e1,x4) & n_tree(x4) & Actor(e1,x1) & v_stand(e1) & subset_of(x3,x1) & n_girl(x3) & subset_of(x2,x1) & n_woman(x2))