3 ms·

Sure they are. You can define a one-to-one mapping, they're equal.

• orbital223 4y ago
  You can define a one-to-one mapping between the sets {1 2} and {3 4}, but I don't think anyone would say they are equal.
• srcreigh 4y ago
  You’re thinking of isomorphic, not equal.
  • chowells 4y ago
    They meant "their cardinalities are equal". It's honestly an easy mistake to make, especially if typing on a small screen. Or especially if having a discussion where sizes of infinity are already being discussed.
    • FabHK 4y ago
      equal in cardinality, yes, thanks.