A man is working to repair a machine.
A man is working on a machine.
man is working to repair a machine.is same as man is working on a machine
exists e1 p1 x1.(Topic(e1,p1) & Actor(e1,x1) & v_work(e1) & exists e2 x2.(Theme(e2,x2) & Actor(e2,x1) & v_repair(e2) & n_machine(x2)) & n_man(x1))
exists e1 x1 x2.(on(e1,x2) & n_machine(x2) & Actor(e1,x1) & v_work(e1) & n_man(x1))