{TAIL ~ Electric arc welder} performs a given weld process with {HEAD ~ selected current waveform} performed between electrode and workpiece  
{ TAIL ~ Electric arc welder } performs a given weld process with { HEAD ~ selected current waveform } performed between electrode and workpiece
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH