Re: representing the dihedral group {1,r,r^2...s,sr^2...}

*To*: mathgroup at smc.vnet.net*Subject*: [mg98890] Re: [mg98796] representing the dihedral group {1,r,r^2...s,sr^2...}*From*: "David Park" <djmpark at comcast.net>*Date*: Mon, 20 Apr 2009 19:15:04 -0400 (EDT)*References*: <27278711.1240205625147.JavaMail.root@n11>

Don't use Times to represent group multiplication, or modify Times and Power. Instead use something like SmallCircle. SmallCircle[s, s^2] You might leave that unevaluated, but then write an EvaluateGroupProducts routine to evaluate the products from a group table or using an algorithm. David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ From: obott0 at gmail.com [mailto:obott0 at gmail.com] Hi, I'm trying to represent the dihedral group {1,r,r^2...s,sr^2...} in mathematica so I can do for example: s^3 and get s. I tried this code: Unprotect[Times, Power]; n = 4; ClearAll[r, s, Times, Power]; SetAttributes[Times, {Flat}] s^2 = 1; r^n = 1; Protect[Times, Power]; But this doesn't work for, for example, s^3. It is not able to simplify it. Thanks a lot! Otto