Comparing terms of expression with Implied sum over indices

*To*: mathgroup at smc.vnet.net*Subject*: [mg126613] Comparing terms of expression with Implied sum over indices*From*: tom u <tumeda at gmail.com>*Date*: Thu, 24 May 2012 03:33:45 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

Does anyone know of a general method to compare terms so that one can simplify expressions with terms that are sums over indices where the the index variables are different? For example, following expression should symbolically equal 0: Sum[f[i],{i,imax}] - Sum[f[j],{j,imax}] The terms with sums can be more complicated and also implicit as in the case of tensor notation. The goal is to have an automatic way to Simplify tensor equations that use different dummy indices. Thank you