{HEAD ~ Model} checking a cutoff number of {TAIL ~ processes} is performed to verify race freedom in the concurrent program 
{ HEAD ~ Model } checking a cutoff number of { TAIL ~ processes } is performed to verify race freedom in the concurrent program
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH