XML Schema Design Issue.

Is it currently possible to do this with XML Schema
I have the following dtd:
<!ELEMENT person (name,pid,sex,(parent,parent?)?,child*) >
<!ElEMENT parent (#PCDATA)>

now my question is that the role must either mother or father, which is
easy to do. But, under the current XML specification, can I, without any
changes to the given DTD make it such that a particular person cannot
accidentally have two mothers or two fathers. How can I enforce that if a
person has two parents listed only one can be role=mother and only one can
be role=father ?

Received on Monday, 27 October 2003 04:36:56 UTC