On 11/18/12 at 5:15 PM, email@example.com (Murray Eisenberg) wrote:
>On Nov 18, 2012, at 3:57 AM, Dave Snead <firstname.lastname@example.org> 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.