Re: A Bug in symbolic summation?

*To*: mathgroup at smc.vnet.net*Subject*: [mg113153] Re: A Bug in symbolic summation?*From*: Christopher Arthur <aarthur at tx.rr.com>*Date*: Fri, 15 Oct 2010 13:52:45 -0400 (EDT)*References*: <201010140327.XAA06188@smc.vnet.net>

Hi Rex, Hold[] and Simplify[] might help. Chris. Fancy Airex a écrit : > I wish to do a basic symbolic manipulation of two summations. > >> Sum[f[i], {i, 0, m}] - Sum[f[i], {i, 0, j}] >> > > but can't get the expected result > >> Sum[f[i], {i, j+1, m}] >> > > > I also tried > >> Sum[f[i], {i, 0, m}] - f[0] >> > > but can't get the expected result > >> Sum[f[i], {i, 1, m}] >> > > > Though when I replace m with any definite number everything works > fine. > > It seems that Mathematica can't change the minimum/maximum value of > the summation variable i above in symbolic calculation... > > > I also tried another system, but failed to do such symbolic computation. > > Did I miss any point here? > > > Best, > Rex > > >

**References**:**A Bug in symbolic summation?***From:*Fancy Airex <aoirex@gmail.com>