Answer questions by MAL; add drawing by Ping.

pep-0280.txt

@@ -394,6 +394,46 @@ Additional Ideas
             self.reflect_bltin_new(key, newvalue)
 
 
+FAQs
+
+    Q. Will it still be possible to:
+       a) install new builtins in the __builtin__ namespace and have
+          them available in all already loaded modules right away ?
+       b) override builtins (e.g. open()) with my own copies 
+          (e.g. to increase security) in a way that makes these new
+          copies override the previous ones in all modules ?
+
+    A. Yes, this is the whole point of this design.  In the original
+       approach, when LOAD_GLOBAL_CELL finds a NULL in the second
+       cell, it should go back to see if the __builtins__ dict has
+       been modified (the pseudo code doesn't have this yet).  Tim's
+       alternative also takes care of this.
+
+    Q. How does the new scheme get along with the restricted execution
+       model?
+
+    A. It is intended to support that fully.
+
+
+Graphics
+
+    Ka-Ping Yee supplied a drawing of the state of things after
+    "import spam", where spam.py contains:
+
+        import eggs
+
+        i = -2
+        max = 3
+
+        def foo(n):
+            y = abs(i) + max
+            return eggs.ham(y + n)
+
+    The drawing is at http://web.lfw.org/repo/cells.gif; a larger
+    version is at http://lfw.org/repo/cells-big.gif; the source is at
+    http://lfw.org/repo/cells.ai.
+
+
 Comparison
 
     XXX Here, a comparison of the three approaches could be added.