Relation Mapping Question

I am using EF 4.1 and POCO model (code only).

I have a Fiche entity which has Id as the primary key. And FicheCancellation entity, which has a Id which holds the Id of the Fiche that is cancelled and a CancellationFicheId which holds the Id of the generated cancellation Fiche's Id

    class Fiche {
       public Guid Id {get; set;}
       ...
       public virtual Fiche CancelledFiche {get; set;}
       public virtual Fiche CancellationFiche {get; set;}
       public virtual FicheCancellation Cancellation {get; set;}
    }
    class FicheCancellation {
        // cancelled FicheId
      开发者_开发百科  public Guid CancelledFicheId {get; set;}
        //generated cancellation ficheId
        public Guid CancellationFicheId {get; set;}

        public virtual Fiche CancelledFiche {get; set;}
        public virtual Fiche CancellationFiche {get; set;}
....
some other fields about the operation
...

    }

now how do I configure navigations above, either with ForeignKey attributes or with ModelBuilder;

1- so that I have access to the cancellation entity.

2- and if the Fiche entity is a cancellation fiche, have a reference to the cancelled fiche.