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