Patent ID: 8121989

Claim:
A method for comparing documents, comprising: identifying a set of matching elements and associated locations of the matching elements in a first document and a second document; repeatedly identifying additional sets of matching elements and associated locations of the matching elements in the first document and the second document until there are no further matches, wherein a given additional set of matching elements is different than the set of matching elements and other additional sets of matching elements; computing an information content of a given set of matching elements; and assigning labels to instances of the set of matching elements based on the computed information content, wherein the labels identify a relationship for the corresponding instances of the set of matching elements, and wherein assigning the labels comprises: assigning a label of ‘unchanged’ to instances of the set of matching elements in the second document if the information content of the set of matching elements is greater than or equal to a pre-determined value; and assigning a label of ‘changed’ to instances of the set of matching elements in the second document if the information content of the set of matching elements is less than the pre-determined value.