precedence rules for attribute specification

IV. please specify the precedence rules for attribute "specification".

there are three states in the following matrix for which i cannot yet specify
the effective binding:
(ed = element default, cd = context default,
 eb = element binding, cb = context binding)

            default presence in attribute declaration
            
attribute
presence in
element        -- --  |  -- ed  |  cd --  |  cd ed
             ---------------------------------------
            | unbound |     ed  |  cd     |  ?   ?  |
     -- --  |         |         |         |  ?   ?  |
            ----------------------------------------
            |         |         |         |         |
     -- eb  |     eb  |     eb  |     eb  |     eb  |
            ----------------------------------------
            |         |  ?   ?  |         |  ?   ?  |
     cb --  |  cb     |  ?*  ?  |  cb!    |  ?   ?  |
            ----------------------------------------
            |         |         |         |         |
     cb eb  |     eb  |     eb  |     eb  |     eb  |
            ----------------------------------------


*: xml-dev discussion has implied that the context binding takes precedence,
but that would lead to capturing prefix bindings on included external entities
- which is not necessarily to be recommended. (see, for example, http://www.lists.ic.ac.uk/hypermail/xml-dev/9808/0152.html)
!: modulo the other ambiguities

i would suggest that the attribute declaration in the dtd should be afforded a
lexical scope which takes precedence over the dynamic scope of any bindings in
the element stream.