Now a moments inspection indicates that deliveryAddress and customerAddress are merely placeholders for the true type of the element (which is Address).
The Vindex is used to find atomic objects satisfying the conditions specified in the query. The Lindex finds all parents 20 H. Rho et al. of an object via an edge with a given label, and the Bindex supports finding all parentchild object pairs connected by a specified label [McHu 99]. 3 1-Index The 1-index  is based on the concept of bisimulation. A binary relation ~ between two nodes v and v’ is called a bisimulation, denoted v ~ v’, and is defined as follows:(1) If v ~ v’ and v is a root, then v’ is a root, too.