Re: problem with Sum

*To*: mathgroup at smc.vnet.net*Subject*: [mg100671] Re: problem with Sum*From*: dh <dh at metrohm.com>*Date*: Wed, 10 Jun 2009 17:12:39 -0400 (EDT)*References*: <h0nugr$b72$1@smc.vnet.net>

Hi, try e.g.: Sum[a[k], {k, Min[i + j - n, j] + 1, Max[i + j - n, j]}] Daniel olfa wrote: > Hi mathematica community, > > I have this input: Sum[a[k], {k, 1, j}] - Sum[a[k], {k, 1, i+j-n}] > How it is possible to let mathematica gives as output: > Sum[a[k], {k, i+j-n+1, j}] if i+j-n<j > and Sum[a[k], {k, j+1, i+j-n}] if i+j-n>j > > thank you very much. >