<Dd> <Ul> <Li> ∅ ⊆ A . </Li> <Li> A ⊆ A . </Li> </Ul> </Dd> <Ul> <Li> ∅ ⊆ A . </Li> <Li> A ⊆ A . </Li> </Ul> <Li> ∅ ⊆ A . </Li> <Li> A ⊆ A . </Li>

Solved example using the three methods of representation of a set