choice group particel whose {particles} is empty

There is a difference between choice and {all, sequence} group particles 
in determining whether its {content type} is empty or whether a particle
is pointless:
   choice -- {particles} is empty plus its {min occurs} is 0
   {all, sequence} -- {particles} is empty

It looks to me that the following two groups are different:
   choice A -- its {minOccurs} = 0 and {particles} is empty
   choice B -- its {minOccurs} = 1 and {particles} is empty

For choice A, its {content type} is empty and it's 
pointless.  For choice B its {content type} is not
empty and it's not pointless because it defines a "negative
group particle" where no sequence (including empty sequence) of
element information items can be valid with respect to it.

Is this interpretation correct?

Thx,

-Stanley