When {HEAD ~ the heat sink} is inserted into {TAIL ~ the computer}, the heat pipe is disengaged from a heat source 
is inserted into
When { HEAD ~ the heat sink } is inserted into { TAIL ~ the computer } , the heat pipe is disengaged from a heat source
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH