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Re: Clear, Remove variables

• To: mathgroup at smc.vnet.net
• Subject: [mg76966] Re: Clear, Remove variables
• From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
• Date: Thu, 31 May 2007 03:14:11 -0400 (EDT)
• Organization: Uni Leipzig
• References: <f3jh9p$ded$1@smc.vnet.net>
• Reply-to: kuska at informatik.uni-leipzig.de

Hi,

due to the internal structure a subscripted symbol
is stored as Subscript[x,1] and not as xAnyChracter1
and the values are associated with Subscript[] and
not with x, i.e.

Subscript[x,1]=4

is a down value to Subscript[] and not to x.
You can clear Subscript[] and this will remove all
values associated with subscripted variables or you can associate
the assigmet

x/: Subscript[x,1]=4

and it will be in the UpValues[] of x and now you can clear
x to remove the value.

You can do what Symbolize[] does and setup a new symbol, that is
read and printed as Subscript[x,1] but is internal stored as
x\[SomeLetterYouWillNeverUse]1

and clear this symbol.

Regards
   Jens



Miguel wrote:
> In version 6.0, I can not to clean variables with subscripts by Clear
> or Remove. Why?.
> 
> Can I to copy and to use the package Utilities`SubscriptSymbols`of 5.2
> version in 6.0 version?
> 
>