{HEAD ~ The heat pump} in {TAIL ~ accordance} 1 or 2, wherein said second reversing means is a four way valve 
{ HEAD ~ The heat pump } in { TAIL ~ accordance } 1 or 2 , wherein said second reversing means is a four way valve
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH