Indirection in Set-Inclusion and Parent-Child structures

Various functions to query entities, entity sets and parent or child sets as well as the numbers of these involve a num_hops argument. If the set upon which the query is originated is the root set, the num_hops argument is irrelevant and is ignored by the implementation. Otherwise, the num_hops argument represents the maximum number of levels of indirection employed in satisfying the query not including the originating set. For example, using value for num_hops of 0 (zero) in iMesh_getEntSets will return all the entity sets that are immediately contained in a given set. Likewise, a value for num_hops of 1 (one) will return all entity sets that are immediately contained in the given set plus all entity sets that are contained in those immediately contained sets (e.g. one level of indirection). Using a value of -1 for num_hops will return results for all possible levels of indirection. In other words, using a value of -1 for num_hops is equivalent to setting the maximum number of levels of indirection to infinity.