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A kernel, multiple notebooks, and Global?

• To: mathgroup at smc.vnet.net
• Subject: [mg87663] A kernel, multiple notebooks, and Global?
• From: AES <siegman at stanford.edu>
• Date: Tue, 15 Apr 2008 05:51:36 -0400 (EDT)
• Organization: Stanford University

Pardon any awkward wordings here, but I may not have all the jargon 
relevant to my query clearly understood.

Suppose that on a single-user computer I have several notebooks open 
that address different parts of a common calculation, and thus share 
overlapping sets of globally used variable names.  

The broad question is then, how far can I go -- or what dangers may lurk 
-- in treating these multiple notebooks as essentially one unified 
notebook that just happens to be stored in multiple files and appear on 
screen in multiple windows?

1)  For example, in terms of contexts or scopes, I'm guessing that 
"Global is Global":  the Global` context for all of these notebooks is 
set by or recorded by the kernel, and at any one instant is exactly the 
same for all these open notebooks  -- right?

2)  Suppose a certain Input cell is present in exactly identical form at 
some random (i.e., different) point in each of the notebooks; I've been 
executing cells from all of the notebooks in some irregular sequence; 
and then I execute this particular cell in whichever of the notebooks 
happens to be most convenient for me.

I assume the kernel is likely to be able to recognize which notebook 
submitted these Input instructions.  But beyond that, unless this cell 
contains some code which directly or indirectly identifies the notebook 
in which the cell resides, and uses this information to modify the Input 
instructions, executing the copy of this cell that resides in any of the 
notebooks will produce exactly the same result, except for where it 
displays its output -- right?