Header file 900 may have {TAIL ~ definitions} of virtual types and values for {HEAD ~ each virtual type} coded in a computer program 
Header file 900 may have { TAIL ~ definitions } of virtual types and values for { HEAD ~ each virtual type } coded in a computer program
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH