       • To: mathgroup at smc.vnet.net
• Subject: [mg44533] Re: Readability confuses mathematica?
• From: Oliver Friedrich <oliver.friedrich at tzm.de>
• Date: Thu, 13 Nov 2003 05:57:51 -0500 (EST)
• Organization: TZ Mikroelektronik
• References: <botcm2\$ci7\$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

```patrick.m.lahey at aero.org (patrick_m_lahey) wrote in news:botcm2\$ci7\$1
@smc.vnet.net:

> I am new to mathematica so perhaps there is a simple answer to this
>
> Consider:
>
> In:= D[x-x0,x]
>
> except that x0 is really x ctrl-- 0 (x subscript 0).  Normally that
> would be a completely independent variable from x but not according to
> mathematica!
>
> Out=1-Subscript(1,0)[x,0]
>
> (the (1,0) is a superscript of Subscript).
>
> One of the things that attracted me to mathematica was the ability to
> work with expressions that closely mirrored the true expressions of
> interest (a readability issue really...).
>
> Is there anything that can be done here?
>
>

Hallo Patrick,

are you using at least Mathematica 4? Then try to use the Notation
package.
The problem is that Mathematica treats expressions like x Subscript 0 not
as a symbol but as a coumpound expression and thus tries to derive the
function Subscript.
The Notation package provides a method called "Symbolize" where you can
kind of transform Compound expressens into real symbols. It seems to add
rules to interpreting input and formatting output. So Subscript[x,0] is
transformed to a symbol called x_Subscript_0. This is treat like a real
symbol. On output it is formatted in a appropriate way.
But I've found that these function don't work correctly when you want to
put out symbolized expressions in TraditionalForm. Maybe anyone out there
who knows an answer to this issue.

Regards
Oliver Friedrich

```

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