{HEAD ~ These decoders} are much lower in complexity compared to {TAIL ~ the standard belief propagation decoder} 
{ HEAD ~ These decoders } are much lower in complexity compared to { TAIL ~ the standard belief propagation decoder }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL