“I” can be used to produce ARs of the form A B, where A and B are disjoint subsets of a large I. The ARs generated are usually pruned according to some notion of confidence in each AR. However to achieve this pruning, it is always necessary to first identify the “large” I contained in the input data. This in turn
requires an effective storage structure. One of the efficient data storage mechanisms for itemset storage is T-tree [15].