"Alternating" function

*To*: mathgroup at smc.vnet.net*Subject*: [mg63260] "Alternating" function*From*: Renan <renan.birck at gmail.com>*Date*: Tue, 20 Dec 2005 23:35:44 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Hello, I want to make a "nested function" like: x + f[x - f[x + f[x - f[x + f[x]]]]]. I've tried using Nest but I don't find how to keep switching between Plus and Minus: I would need something that would return an "index" so I could keep track of when I need to "switch" the operation. (e.g. if the "index" is odd, the operation is "Plus", otherwise is "Minus") How can I make this? I looked in the help but didn't find any informations. Thanks. -- Thanks/obrigado, Renan "Wishmaster" Birck - Canoas, Rio Grande do Sul, Brasil MSN: wizard_of_yendor at hotmail.com Orkut: http://www.orkut.com/Profile.aspx?uid=2202360379963855296

**Follow-Ups**:**Re: "Alternating" function***From:*Sseziwa Mukasa <mukasa@jeol.com>

**Re: "Alternating" function***From:*ggroup@sarj.ca