ini gimana maksudnya ?

Kalo ndak salah kayak gini
{a,b}⇒bnyk anggota = 2 ⇒himp. bag. P = { },{a},{b},{a,b}⇒bnyk himp. bag n(P(A)) = 4 = 2²
{a,b,c}⇒bnyk anggota = 3⇒himp. bag. P = { },{a},{b},{c},{a,b},{b,c},{a,c},{a,b,c}⇒bnyk himp. bag. n(P(A)) = 8 = 2³