Thus, {HEAD ~ each block} may have a single specification in block specifications 504 that may be used to generate {TAIL ~ either a software or hardware implementation} of the block 
Thus , { HEAD ~ each block } may have a single specification in block specifications 504 that may be used to generate { TAIL ~ either a software or hardware implementation } of the block
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH