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Subscript[x,1] value do not get cleared using Clear["Global`*"] but get removed using Remove["Global`*]

• To: mathgroup at smc.vnet.net
• Subject: [mg104033] Subscript[x,1] value do not get cleared using Clear["Global`*"] but get removed using Remove["Global`*]
• From: "Nasser M. Abbasi" <nma at 12000.org>
• Date: Fri, 16 Oct 2009 07:20:02 -0400 (EDT)
• Reply-to: "Nasser M. Abbasi" <nma at 12000.org>

Hello,
Version 7 on XP Sp2

Before, I used to use Clear["Global`*] to clear all variable, until I just 
found subscripted variable do not get cleared

In[31]:= Remove["Global`*"]

In[33]:= Subscript[a, 1] = 5

In[34]:= Subscript[a, 1]
Out[34]= 5

In[35]:= Clear["Global`*"]    --> now clear it

In[36]:= Subscript[a, 1]
Out[36]= 5      ----> did not clear

In[37]:= Remove["Global`*"]
In[38]:= Subscript[a, 1]

Out[38]= Subscript[a, 1]   ---> ok, removed

I find the above a bit strange. I first thought may be becuase I did not 
"symbolize" a_1 using the notation package, but even after doing that, a_1 
would still not be cleared of its value:

In[59]:= Remove["Global`*"]
In[60]:= << "Notation`"

In[61]:= Symbolize[ParsedBoxWrapper[\(a\_1\)]]

In[62]:= Subscript[a, 1] = 5
Out[62]= 5

In[63]:= Clear["Global`*"]   --> now clear it

In[64]:= Subscript[a, 1]
Out[64]= 5   ----> did not clear

In[65]:= Remove["Global`*"]

In[66]:= Subscript[a, 1]
Out[66]= Removed[a\[UnderBracket]Subscript\[UnderBracket]1]

I thought the above should make it so that a_1 is now "one" symbol, and it 
should have been cleared?

So now, to make sure I am starting with clean computation, I either will do 
Remove[...] or restart the kernel.

Do you find this strange or is it just me?

--Nasser