Recursive Elements

[doubledgedboard]

Is there a way to model a recursive element?

e.g.

<foos>
    <foo>
        <bar>hello world</bar>
        <foos>
            <foo>
                <bar>blah blah</bar>
                <foos/>
            </foo>
        </foos>
    </foo>
</foos>

where a list of foos has a foo which itself may have a list of foos