Customers wait in line while the workers in green shirts help them.
The people in green shirts are helping the customers.
The workers in green shirts help them  implies workers are helping customers.
exists e1 p1 x1 x2 x3.(n_worker(x3) & exists e2 s1 x4.(Theme(e2,x1) & Actor(e2,x3) & v_help(e2) & in(x3,x4) & n_shirt(x4) & a_green(s1) & Theme(s1,x4)) & n_thing(x1) & while(e1,p1) & in(e1,x2) & n_line(x2) & Actor(e1,x1) & v_wait(e1) & n_customer(x1))
exists e1 s1 x1 x2 x3.(n_customer(x3) & n_people(x1) & Theme(e1,x3) & Actor(e1,x1) & v_help(e1) & in(x1,x2) & n_shirt(x2) & a_green(s1) & Theme(s1,x2))