1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Power Set Of A Power Set

  1. Sep 30, 2012 #1
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
    I did the inner power set first: {{∅}, ∅}
    Then I took the power set of that: {{{∅}}, {∅}, {{∅}, ∅}, ∅}
    But according to the answer, there is only two elements.
  2. jcsd
  3. Sep 30, 2012 #2
    That first power set doesn't look quite right to me.

    is {∅} an element of ∅??

    What are all the elements of ∅?

    What are all the subsets of ∅?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook