Length of the largest chain of a poset ordered by set inclusion.

44 Views Asked by At

If $E4$ is the set of all equivalence relations on $\{1,2,3,4\}$,and we define a poset as

$(E4, \{(R1,R2) \in E4 \times E4 \mid R1 \subseteq R2\})$

then what would be the length of largest chain of this poset?