| 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.