  Itemset mining is one of the most studied tasks in knowledge discovery. In
this paper we analyze the computational complexity of three central itemset
mining problems. We prove that mining confident rules with a given item in the
head is NP-hard. We prove that mining high utility itemsets is NP-hard. We
finally prove that mining maximal or closed itemsets is coNP-hard as soon as
the users can specify constraints on the kind of itemsets they are interested
in.
