True if GraphA and GraphB are the same under Substition.
Substition is a list of BNodeA = BNodeB, where BNodeA is a
blank node that appears in GraphA and BNodeB is a blank node
that appears in GraphB.
GraphA
is a list of rdf(S,P,O)
terms
GraphB
is a list of rdf(S,P,O)
terms
Substition
is a list if NodeA = NodeB terms.
To be done
The current implementation is rather naive. After dealing with the
subgraphs that contain no bnodes, it performs a fully non-deterministic
substitution.