Two kids in a green tree.
A pair of children in a tree.
Two kids implies pair of children
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 x1 x2 x3.(a_topic(x1) & of(x1,x2) & in(x2,x3) & n_tree(x3) & n_child(x2) & n_pair(x1))