{HEAD ~ A software module} may comprise {TAIL ~ a single instruction}, or many instructions, and may be distributed over several different code segments, among different programs and across multiple storage media 
comprise
{ HEAD ~ A software module } may comprise { TAIL ~ a single instruction } , or many instructions , and may be distributed over several different code segments , among different programs and across multiple storage media
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH