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