Re: Subscript on plus expression

*To*: mathgroup at smc.vnet.net*Subject*: [mg128706] Re: Subscript on plus expression*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Mon, 19 Nov 2012 04:07:57 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net

On 11/18/12 at 5:15 PM, murray at math.umass.edu (Murray Eisenberg) wrote: >On Nov 18, 2012, at 3:57 AM, Dave Snead <dsnead6 at charter.net> wrote: >>Mathematica fails to parenthesize the a+b in Subscript[Plus[a,b],k] >>so the output looks identical to Plus[a,Subscript[b,k]] >>Is this a bug? Is there an option to force the parentheses? >I don't know off hand of any such option, but is it so unreasonable >to insert parentheses explicitly in the first? After all, that's >surely what you'd do if writing it with pencil on paper! That won't help since Mathematica will evaluate (a+b) to a+b removing the parentheses before the full expression is evaluated. The only way I can think of to create something that at least looks like a subscripted sum would be to enter it in a manner where Mathematica will not evaluate any part of it. For example, I could set the input cell format to be a text cell then create the expression. Of course the end result isn't something that can be used in other computations.