Workers on a roof install new shingles.
The workers are shingling the roof.
Workers install new singles means that they are shingling the roof.
exists e1 s1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_install(e1) & n_shingle(x3) & a_new(s1) & Theme(s1,x3) & on(x1,x2) & n_roof(x2) & n_worker(x1))
exists e1 x1 x2.(n_roof(x2) & n_worker(x1) & Theme(e1,x2) & Actor(e1,x1) & v_shingle(e1))