In {TAIL ~ one embodiment}, each global interface includes {HEAD ~ a request agent} , a directory agent and a slave agent  
In { TAIL ~ one embodiment } , each global interface includes { HEAD ~ a request agent } , a directory agent and a slave agent
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH