16. The method of claim 12 , wherein the first set of data values is stored in a first node function matrix and the second set of data values is stored in a second node function matrix, and the step of determining whether a sufficient degree of correlation exists comprises comparing values stored in like cells of the node function matrices.
16. The method of claim 12 , wherein the first set of data values is stored in a first node function matrix and the second set of data values is stored in a second node function matrix, and the step of determining whether a sufficient degree of correlation exists comprises comparing values stored in like cells of the node function matrices. 17. The method of claim 16 , further comprising generating said combined extraction rule based substantially on an intersection between the first and second node function matrices.