Let $A=\{a,b,c,d,e,f\}$, $R$ is defined by: $\{(a,b), (c,d),(d,c),(d,a),(d,b),(d,f),(e,a),(e,b),(e,c),(e,d),(e,f),(f,a),(f,b)\} \cup \Delta_A$.
I am not sure on how to draw a Hasse Diagram for $R$.
I start of with the non empty set which is in relation with $a,b,c,d,e,f$. Then the other ordered pairs would be $(a,b),(a,c),(a,d),(a,e),(a,f),(b,c),(b,d),(b,e),(b,f), (c,d),(c,e),(c,f),(d,e),(d,f),(e,f)$.
Is there another layer above these ordered pair. I don't knw how to complete the Hasse Diagram. Any help/information will help..
thank you!