Re: pretty output with HoldForm

*To*: mathgroup at smc.vnet.net*Subject*: [mg70482] Re: pretty output with HoldForm*From*: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>*Date*: Tue, 17 Oct 2006 02:59:30 -0400 (EDT)*Organization*: Uni Leipzig*References*: <egva7f$rgs$1@smc.vnet.net>

Hi, kl[n_] := HoldForm[ 1/(2n + 1) - 1/(4n + 2) - 1/(4n + 4)]; reihe = Sum[kl[n], {n, 1, 5}]; (reihe + Hold[] //. HoldForm[a_] + b_. + Hold[c___] :> (d = Evaluate[a]; Append[Hold[c], d] + b)) /. Hold[c___] :> HoldForm[Plus[c]] Regards Jens "Peter Breitfeld" <phbrf at t-online.de> schrieb im Newsbeitrag news:egva7f$rgs$1 at smc.vnet.net... | | I want to get the following output for the series: | | (1 - 1/2 - 1/4) + (1/3 - 1/6 - 1/8) + (1/5 - 1/10 - 1/12) + | (1/7 - 1/14 - 1/16) . . . | | What I did was | | kl[n_]:=HoldForm[ 1/(2n+1)-1/(4n+2)-1/(4n+4)] | | then I enter eg: | | reihe= Sum[kl[n],{n,1,5}] | | This works quite good, but the fractions are completely unevaluated | (because of HoldForm, I know) and display as | | 1 | ---------- | 4 2 + 2 | | But I want them displayed as | | 1 | -- | 10 | | Is there a way to evaluate parts inside a HoldForm, so that the | fractions are evaluated but not the sums? | | Gruss Peter | -- | ==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-== | Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de |