The system 4 in which {HEAD ~ the means} for providing {TAIL ~ a test signal} is a video signal storage and retrieval system 
for providing
The system 4 in which { HEAD ~ the means } for providing { TAIL ~ a test signal } is a video signal storage and retrieval system
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH