Looks like [tex]A[/tex] is the set [tex]\{1,\{0\}\}[/tex], and you want to find the power set of [tex]A[/tex], [tex]\mathcal P(A)[/tex]. [tex]A[/tex] contains only 2 elements, so we expect [tex]2^2=4[/tex] elements in the power set:
[tex]\mathcal P(A)=\{\{\},\{1\},\{\{0\}\},\{1,\{0\}\}\}[/tex]
