Two kids in a green tree.
A boy and girl in a tree.
The kids could be two boys or two girls or a boy and a girl.
exists s1 x1 x2.(a_topic(x1) & in(x1,x2) & n_tree(x2) & a_green(s1) & Theme(s1,x2) & n_kid(x1) & card_eq_2(x1))
exists s1 x1 x2 x3.(a_topic(s1) & subset_of(x2,s1) & in(x2,x3) & n_tree(x3) & n_girl(x2) & subset_of(x1,s1) & n_boy(x1))