{{1,2}, {2,3}, {1,3}}
{} < {1} < {1,2} < {2,3} < {4,2,3}
{ bag [1,1,1], bag [2,2,2,2,2] }
⟅⟆ < ⟅1⟆ < ⟅1,1⟆ < ⟅2⟆ < ⟅2, 2⟆ < ⟅2, 2, 3, 3⟆ < ⟅2, 2, 2, 3⟆ < ⟅2, 2, 2, 4⟆ < ⟅3⟆
