I can't understand the rows & columns of the matrix. Could you
provide some examples? In particular I can't understand
what you mean by "default presence in attribute declaration"
and "attribute presence in element".
Surely you're not talking about default attribute values in
<!ATTLIST declarations? If so, that's a non-issue; the defaults
are there if it's not explicitly specified, they're not there if
it is explicitly specified, there can be no ambiguity. -Tim