#sdf 1.4.32

def "Ref"
{
    def "A" (
        specializes = </Ref/B>
    )
    {
    }

    class "B" (
        inherits = </Ref/C>
    )
    {
    }

    class "C" (
        specializes = </Ref/D>
    )
    {
    }

    class "D"
    {
    }
}