Query relating to Formal Grammar for RDF

The formal grammar for RDF (see www.w3.org/TR/REC-rdf-syntax) indicates 
that a container cannot be a child element of a property element. 
Therefore, RDF statements like this are illegal, no?:


<books> 
       <rdf:Bag> 
             <rdf:_1 resource="Matilda"/> 
             <rdf:_2 resource="The BFG"/> 
       </rdf:Bag> 
</books>


Obviously, they're not, but according to the formal grammar, they are!

Here's a rough diagram which shows how containers and property elements
are seperated in the grammar, and therefore containers can't be children
of property elements.


[<rdf:RDF>] obj* [</rdf:RDF>]
                 |
                 |
|----------------------------------------------------------------------------------------------------------|
|                                                                                                          |
|                                                                                                          | 
Description                                                                                          Container
|                                                                                                          |
|                                                                                                          |               
<rdf:Desc> iAA? bIA? pAttr* > propertyElement* </rdf:Desc>           seq|bag|alt

I must be missing something here, I'd really appreciate it if someone
could help me!