providing fuel, via a fuel conduit, to a plurality of oxidizers coupled in series in an opening in the formation, wherein {HEAD ~ an oxidizer} that first receives fuel from the fuel conduit is {TAIL ~ a first oxidizer} 
is
providing fuel , via a fuel conduit , to a plurality of oxidizers coupled in series in an opening in the formation , wherein { HEAD ~ an oxidizer } that first receives fuel from the fuel conduit is { TAIL ~ a first oxidizer }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL