A worker working on a stone project.
A stone mason student is working his final project.
The worker does not have to be a stone mason student.  The project does not necessarily have to be a final project.
exists e1 x1 x2 x3 x4.(a_topic(x1) & on(e1,x3) & n_project(x3) & of(x3,x4) & n_stone(x4) & Actor(e1,x2) & v_work(e1) & (x1 = x2) & n_worker(x1))
exists e1 s1 x1 x2 x3 x4.(Theme(e1,x4) & Actor(e1,x1) & v_work(e1) & n_project(x4) & a_final(s1) & Theme(s1,x4) & of(x4,x1) & n_male(x1) & n_student(x1) & of(x1,x3) & n_mason(x3) & of(x1,x2) & n_stone(x2))