I am having trouble with this thing. It says,
Let A={ø, {ø}, {{ø}}}.
(a) Determine which of the following are elements of A: ø, {ø}, {ø,{ø}}.
(b) Determine |A|
(c) Determine which of the following are subsets of A: ø, {ø}, {ø,{ø}}.
For d-i, determine the indicated sets.
(d) ø∩A
(e) {ø}∩A
(f) {ø,{ø}}∩A
(g) ø∪A
(h) {ø}∪A
(i) {ø,{ø}}∪A
For A, I got ø, {ø}
B, 3
C, ø,{ø}
D, ø
E, {ø}
F, nothing
Now, I'm just not sure what I'm doing. It's all these stupid empty sets.