> Also, in "Python language reference" it should not be in the grammar definition chapter. There should be a chapter of the execution model before the grammar definition chapter.
After that, I search some keyword on Google and answered as follows.
> It is written in "9.2. Scope and namespace of Python" of "Python tutorial."
> Also, it is in the section "naming and binding" in "Python language reference."
Mr. X is not an inferior programmer than me. The difference between he and me is that I knew the rough structure of the Python documents. *23
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*23
What Mr. X saw was 7. Simple statements > 7.12. The global statement.
I show him is 4. Execution model > 4.2. Naming and binding > 4.2.2. Resolution of names.