HoldForm and Sum

*To*: mathgroup at smc.vnet.net*Subject*: [mg121769] HoldForm and Sum*From*: dimitris <dimmechan at yahoo.com>*Date*: Sat, 1 Oct 2011 03:07:48 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

Hell to all. A (well-known) nice example of the use of HoldForm is: Sum[(HoldForm[#1] & )[i], {i, 1, 10}] (*output omited*) I want to do the same with 1/i Sum[(HoldForm[#1] & )[1/i], {i, 1, 10}] Mathematica output is 1/10+1/9+1/8+...+1/3+1/2+1 My first question is how can I get the output in the form 1+1/2+1/3...+1/8+1/9+1/10 My second query comes now. How can I combine HoldForm and Sum (or anything else) in order to have the following output (unevaluated)? 1+1/2+1/3-1/4-1/5-1/6+1/7+1/8+1/9-1/10-1/11-1/12 that is, three positive terms after three negative and so on. Thank you in advance for your response.

**Follow-Ups**:**Re: HoldForm and Sum***From:*"Tong Shiu-sing" <sstong@phy.cuhk.edu.hk>

**Re: HoldForm and Sum***From:*Gabriel Landi <gtlandi@gmail.com>