Patent ID: 8892564

Claim:
A computer-implemented method of indexing data representable as a directed graph including at least one directed link, each directed link linking a parent node to a child node, the data including items of information data attached to respective nodes, the method comprising: identifying each of the nodes as either an indexable node or a non-indexable node so as to yield at least one indexable parent node and at least one non-indexable parent node; identifying each of the items of information data and each of the directed links as indexable or non-indexable, wherein at least one non-indexable node has a non-indexable parent node and an indexable item of information attached to said at least one non-indexable node; indexing each item of indexable information data, for which the respective node is indexable, to its respective node; indexing each item of indexable information data, for which a parent node of the respective node is indexable and the respective node is non-indexable, to the parent node; and indexing each of at least one indexable item of information, for which the respective node and a parent of the respective node are both non-indexable, as relating to any one or more indexable parent nodes that are linked to its respective node starting from the indexable node and linked to the respective node through a chain of one or more indexable directed links in the direction from parent node to child node passing through the non-indexable parent node and without passing through any indexable nodes.