A little boy is sitting down reading a book.
He's sitting on a chair
A little boy sitting down is not necessarily sitting on a chair.
exists e2 e1 s1 s2 x1 x2.(for(e1,e2) & Theme(e2,x2) & Actor(e2,x1) & v_read(e2) & n_book(x2) & a_down(s2) & Manner(e1,s2) & Actor(e1,x1) & v_sit(e1) & n_boy(x1) & a_little(s1) & Theme(s1,x1))
exists e1 x1.(on(e1,x1) & n_chair(x1) & Actor(e1,x1) & v_sit(e1) & n_male(x1))