EF4.1 and Left Outer Join to find nulls?
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I have two tables, Address & People.  People has FK to Address. I'm trying to find addresses where there are no people:

    select id from Address a 
    left outer join person p on p.address_id = a.id
    where p.address_id is null


Is this possible using LINQ to Entities? I tried a few variations around 

     var results = from addr in _context.Addresses
                   from ppl in addr.People
                   where ppl == null ...

but can't seem to figure out how to return addresses where there are no people.
