Rule R2 of 122 instructs {HEAD ~ the mashup} to fetch some recent news articles from a designated news source, such as {TAIL ~ the Wall Street Journal}, and cache them at browser cache 132 
Rule R2 of 122 instructs { HEAD ~ the mashup } to fetch some recent news articles from a designated news source , such as { TAIL ~ the Wall Street Journal } , and cache them at browser cache 132
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH