Assume there exists an XML instance document that looks like this:

<root>
    <object type="foo">
        <!-- ... -->
    </object>

    <object type="bar">
        <!-- ... -->
    </object>
</root>

My goal is to have a small (static) schema that verifies proper <element type="xxx" /> syntax for objects, and another schema (more prone to change) that verifies the contents of each object element against a complexType that matches the type attribute:

<complexType name="foo"><!--should match object with type="foo"--></complexType>
<complexType name="bar"><!--should match object with type="bar"--></complexType>

What is the best way to accomplish this (or something similar)?