Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Is the empty set disjoint with itself?

  1. Sep 15, 2009 #1
    My apologies if the following is a stupid question. But is the empty set disjoint with itself? Certain aspects of set theory has always been counter-intuitive for me.

  2. jcsd
  3. Sep 15, 2009 #2


    User Avatar
    Science Advisor

    Yes, it is certainly true that [tex]\oslash\cap\oslash=\oslash[/tex].
  4. Sep 16, 2009 #3
    If A and B are not disjoint, it means there is some element belonging to both of them. Anyone who claims the empty set is not disjoint from itself must provide us with an element belonging to the empty set!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook