Figure 1:

Toy example to demonstrate how frequent itemsets and association rules can be derived from a series of transactions. Transactions are indicated by circular boxes, and are labeled as (tid, I), where tid is the transaction identifier and I = {i₁, … , i_k} is an itemset containing the items i₁ to i_k. Frequent itemsets are represented as a squared box, and association rules are shown as an octagonal box.