The first interface is arranged to connect the computers, and the first interface has a port for connecting {HEAD ~ a network interface} of {TAIL ~ the computers} 
The first interface is arranged to connect the computers , and the first interface has a port for connecting { HEAD ~ a network interface } of { TAIL ~ the computers }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL