The program takes as input an initial data set that contains probabilistic information and returns as output {HEAD ~ a sequence} of {TAIL ~ elementary operations}  
of
The program takes as input an initial data set that contains probabilistic information and returns as output { HEAD ~ a sequence } of { TAIL ~ elementary operations }
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