A construction worker assembles a scaffold.
The scaffold was assembled by the worker.
If the worker is assembling the scaffold, then the scaffold was necessarily assembled by the worker.
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_assemble(e1) & n_scaffold(x3) & n_worker(x1) & of(x1,x2) & n_construction(x2))
exists e1 x1 x2.(n_worker(x2) & n_scaffold(x1) & Actor(e1,x2) & Theme(e1,x1) & v_assemble(e1))