a boy walks through the lawn.
A boy testing the grass length .
The reason the boy walks through the lawn is to test the grass length.
exists e1 x1 x2.(n_lawn(x2) & through(e1,x2) & Actor(e1,x1) & v_walk(e1) & n_boy(x1))
exists e1 x1 x2 x3 x4.(n_length(x3) & of(x3,x4) & n_grass(x4) & a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_test(e1) & (x1 = x2) & n_boy(x1))