code: def determine_extended_chord6(chord, shorthand=False, no_inversions=False,
          no_polychords=False):
      
      if len(chord) != 6:
          # warning raise exeption: not an extended chord
          return False
  
      def inversion_exhauster(
          chord,
          shorthand,
          tries,
          result,
          polychords,
          ):
          """Recursive helper function"""
  
          # Determine polychords
          if tries == 1 and not no_polychords:
              polychords += determine_polychords(chord, shorthand)
  
          def add_result(short):
              result.append((short, tries, chord[0]))
  
          ch = determine_extended_chord5(chord[:5], True, True, True)
          intval5 = intervals.determine(chord[0], chord[5])
          for c in ch:
              c = c[len(chord[0]):]
              if c == '9':
                  if intval5 == 'perfect fourth':
                      add_result('11')
                  elif intval5 == 'augmented fourth':
                      add_result('7#11')
                  elif intval5 == 'major sixth':
                      add_result('13')
              elif c == 'm9':
                  if intval5 == 'perfect fourth':
                      add_result('m11')
                  elif intval5 == 'major sixth':
                      add_result('m13')
              elif c == 'M9':
                  if intval5 == 'perfect fourth':
                      add_result('M11')
                  elif intval5 == 'major sixth':
                      add_result('M13')
          if tries != 6 and not no_inversions:
              return inversion_exhauster([chord[-1]] + chord[:-1], shorthand,
                      tries + 1, result, polychords)
          else:
              res = []
              for r in result:
                  if shorthand:
                      res.append(r[2] + r[0])
                  else:
                      res.append(r[2] + chord_shorthand_meaning[r[0]] +
                              int_desc(r[1]))
              return res + polychords
      return inversion_exhauster(chord, shorthand, 1, [], [])
docs: Determine the names of an 6 note chord.