Yes.Originally Posted byhain

No. {∅} contains ∅, {∅} and ∅ are not thesame set. The first is theThis is because {∅} would contain itself right?

set with one element which is the empty set, while the other is the empty

set.

No, {{∅}} has one element {∅}.2.

If 1, then I'd assume that |{{∅}}|=2?

|{∅,{∅}}|=2, {∅,{∅}} is a set with two elements ∅, and {∅}.Further, what would the cardinality of the following sets be:

a. {∅,{∅}}

{∅} has one element ∅, {{∅} } has one element {∅}, and as ∅ is notb. {∅} ∩ {{∅}} (and what does this set contain? quite confusing)

equal to {∅} the intersection is empty so

{∅} ∩ {{∅}} = ∅

Yes.c. {{∅},∅} (this set is the same as a. I believe)

RonLActually if anyone could also let me know which of these sets is equal I think it might help me figure it out. Anyway I'm just trying to undertand empty set a little because my textbook just glazes over it. Thanks~!