providing {HEAD ~ a cap} having {TAIL ~ a third lock element} which mates with a fourth lock element on said cylinder; and 
having
providing { HEAD ~ a cap } having { TAIL ~ a third lock element } which mates with a fourth lock element on said cylinder ; and
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH