A lady working on a machine.
a lady is watching someone else work on a machine
A lady is working while a lady is watching.
exists e1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_machine(x3) & Actor(e1,x2) & v_work(e1) & (x1 = x2) & n_lady(x1))
exists e1 e2 x1 x2 x3 x4.(Theme(e2,x2) & Actor(e2,x1) & v_watch(e2) & on(e1,x4) & n_machine(x4) & Actor(e1,x3) & v_work(e1) & (x2 = x3) & r_else(x2) & n_person(x2) & n_lady(x1))