f) setting {HEAD ~ electric power supplies} in {TAIL ~ contact} with the side surfaces of said two elements, 
in
f ) setting { HEAD ~ electric power supplies } in { TAIL ~ contact } with the side surfaces of said two elements ,
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH