{HEAD ~ These operations} of vertical and horizontal edges can be expanded to have {TAIL ~ coefficients} of a, −a, 0, or aj as before 
{ HEAD ~ These operations } of vertical and horizontal edges can be expanded to have { TAIL ~ coefficients } of a , −a , 0 , or aj as before
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH