{TAIL ~ a push button array} including a plurality of push buttons for accomplishing {HEAD ~ various vacuum valving functions}, 
{ TAIL ~ a push button array } including a plurality of push buttons for accomplishing { HEAD ~ various vacuum valving functions } ,
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH