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