For example, {HEAD ~ a keyboard} 34 may be used for {TAIL ~ interaction} with the user, as may a mouse 36 
used for
For example , { HEAD ~ a keyboard } 34 may be used for { TAIL ~ interaction } with the user , as may a mouse 36
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH