Bag

In math­e­mat­ics, a “bag” is an un­ordered list. A bag differs from a set in that it can con­tain the same value more than once. A bag differs from a list in that its el­e­ments are not or­dered. For ex­am­ple, \(\operatorname{Bag}(1, 1, 2, 3) = \operatorname{Bag}(2, 1, 3, 1) \neq \operatorname{Bag}(1, 2, 3).\)