/*=============( Shell sort )=============*/
SSort: Procedure Expose stem.

Do n = 2 While 2 ** n < stem.0;  End

Do m = n - 1 To 1 By -1
  k = 2**m - 1

  Do i = 1 to stem.0 - k
    j = i
    n = j + k

    x = stem.n
    Do While x << stem.j & j > 0
      stem.n = stem.j
      n = j
      j = j - k
    End
    stem.n = x
  End
End

Return ''
/*** End SSort ***