{HEAD ~ The barcode} has I first columns of modules and J rows of {TAIL ~ modules} transverse to columns 
{ HEAD ~ The barcode } has I first columns of modules and J rows of { TAIL ~ modules } transverse to columns
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH