Both address {HEAD ~ sequencers} 20 and 30 generate {TAIL ~ a next address} based upon the current address and the value sampled using the current address 
generate
Both address { HEAD ~ sequencers } 20 and 30 generate { TAIL ~ a next address } based upon the current address and the value sampled using the current address
OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH