Set-Theory

Suppose A = {a,b,c,d} and Π₁ is the following partition of A
Π₁ = {{a,b,c}{d}}

(a) List the ordered pairs of the equivalence relations induced by Π₁.

(b) Draw the graph of the above equivalence relation.

(c) Let Π₂ = {{a},{b},{C},{d}}
Π₃ = {{a,b,c,d}}
and Π₄ = {{a,b},{c,d}}

Draw a Poset diagram of the poset,
({Π₁,Π₂,Π₃,Π₄}, refines⟩