function ReverseStrR(const S: string): string;
begin
  if SysUtils.AnsiSameText(S, SysUtils.EmptyStr) or (System.Length(S) = 1) then
    Result := S
  else
    Result := StrUtils.RightStr(S, 1)
      + ReverseStrR(StrUtils.LeftStr(S, System.Length(S) - 1))
end;
//delphi/2325