----- Original Message -----
From: "Mauricio FernáÏdez" <batsman.geo / yahoo.com>

So Class is at the top of the singleton classes' inheritance chain.
Interesting loop

               Class
                 ^
    Object --> Object'
      ^          ^
    Module --> Module'
      ^          ^
    Class  --> Class'
----------------------------

I think the rule for determining the superclass of obj's singleton class is
this:

If obj has a superclass (i.e. all classes but Object), then use the
superclass's singleton class.  (So `superclass' and `singleton_class'
operations commute.)

Otherwise, just use `obj.class'.

Chris