A little boy streches his body out with his stomach on the grass.
The boy is on the grass.
Since his stomach is on the grass that means the boy is on the grass.
exists e1 s1 s2 x1 x2 x3 x4.(n_grass(x4) & with(e1,x3) & on(x3,x4) & n_stomach(x3) & of(x3,x1) & n_male(x1) & n_male(x1) & a_out(s2) & Manner(e1,s2) & Theme(e1,x2) & Actor(e1,x1) & v_strech(e1) & n_body(x2) & of(x2,x1) & n_boy(x1) & a_little(s1) & Theme(s1,x1))
exists p1 x1 x2.(n_grass(x2) & n_boy(x1) & on(x1,x2))