Symbolic Sum or Sum???

*To*: mathgroup at smc.vnet.net*Subject*: [mg4256] Symbolic Sum or Sum???*From*: am4a056 at rzaix42.uni-hamburg.de (Rene Garizzao)*Date*: Sun, 23 Jun 1996 03:08:46 -0400*Organization*: University of Hamburg -- Germany*Sender*: owner-wri-mathgroup at wolfram.com

Actually I have a problem for solving a double sum whose limits are running from ( - Infinity ) to ( + Infinity ). I attempted this sum in several ways without a satisfactory result: 1-Attempt) : =========== Needs["Algebra`SymbolicSum`"] BeginPackage["Algebra`","SymbolicSum`"] F[x0_,y0_, N_, M_,n_,m_]:= 1/((x0 + n N)^2 + (y0 + m M)^2)^(3/2) SymbolicSum[F[x0,y0,N,M,n,m] , {m,Infinity}, {n,Infinity} ] NSum[ F[1,0,3,3,n,m] , {m,-infinity,Infinity}, {n,-Infinity,Infinity} ] S[k_]:= NSum[ F[1,0,3,3,n,m] , {m,-k,k}, {n,-k,k} ] Table[S[i],{i,0,Infinity}] None of this this forma could bring me further in the solution of F[...]. I thank you in advance for any help you can provide me. ==== [MESSAGE SEPARATOR] ====