A little girl in a yellow shirt holding a big snail.
A little girl ate the snail
The subject cannot be both the one who ate the snail and be one holding it.
exists e1 s1 s2 s3 x1 x2 x3 x4.(a_topic(x1) & in(x1,x2) & Theme(e1,x4) & Actor(e1,x3) & v_hold(e1) & n_snail(x4) & a_big(s3) & Theme(s3,x4) & (x2 = x3) & n_shirt(x2) & a_yellow(s2) & Theme(s2,x2) & n_girl(x1) & a_little(s1) & Theme(s1,x1))
exists e1 s1 x1 x2.(n_snail(x2) & Theme(e1,x2) & Actor(e1,x1) & v_eat(e1) & n_girl(x1) & a_little(s1) & Theme(s1,x1))