{HEAD ~ A first fixed reflecting surface} of a parabolic group reflecting surface can include a focus on the second focus of the first reflecting surface, and {TAIL ~ at least two second reflecting surface elements} 
include
{ HEAD ~ A first fixed reflecting surface } of a parabolic group reflecting surface can include a focus on the second focus of the first reflecting surface , and { TAIL ~ at least two second reflecting surface elements }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL