Children climb a tree.
Two boys climb an oak tree.
Not all children are boys.
all x1.(n_tree(x1) -> exists x2 x3.(a_topic(x2) & for(x2,x1) & n_climb(x2) & (x2 = x3) & ne_nam_children(x3)))
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_climb(e1) & n_tree(x2) & of(x2,x3) & n_oak(x3) & n_boy(x1) & card_eq_2(x1))