11. The computer implemented system of claim 10 , wherein said modifying module modifies said at least one branch of the data structure.
10. The computer implemented system of claim 9 , wherein said modifying module comprises: an identification module for identifying, in a current generation of Nondeterministic Finite Automaton (NFA) said current generation of NFA comprising compiled Xpath query group maintained as a data structure, at least one branch of said data structure starting from root node according to the modification request; and a copying module for creating a copy of the identified at least one branch of the data structure.