The method involves passing editor input to the external program, wherein {HEAD ~ the external program} evaluates the input, produces {TAIL ~ corresponding output}, and transmits the output back to the editor 
produces
The method involves passing editor input to the external program , wherein { HEAD ~ the external program } evaluates the input , produces { TAIL ~ corresponding output } , and transmits the output back to the editor
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH