For a block that may be designated for implementation in either software or hardware, the block may have {HEAD ~ a specification} in {TAIL ~ block specifications} 504 that is either a specification in a general purpose programming language or a specification in a hardware description language 
For a block that may be designated for implementation in either software or hardware , the block may have { HEAD ~ a specification } in { TAIL ~ block specifications } 504 that is either a specification in a general purpose programming language or a specification in a hardware description language
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 REL 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