17. A method according to claim 16, further comprising the steps of: finishing processing of said hierarchical level B and deleting said plurality of references for the level B in said primary data structure; and using said plurality of references for the level A when processing at the hierarchical level A, after the deleting of said plurality of references for the level B.
16. A method according to claim 13, further comprising the steps of: inputting an element at the hierarchical level B indicating a second dictionary is to be generated and generating said second dictionary; and changing the reference used for keeping track of dictionaries at the hierarchical level B to refer first to said second generated dictionary and refer second to said first generated dictionary.