For 2 sets A, B, A is called a proper subset of B iff
A ≠ B
A ⊂ B
A = B
A ⊂ B and A ≠ B
For 2 sets A, B, A is called a proper subset of B if A ⊂ B and A ≠ B.
When is A called proper subset of B?
No set is a proper subset of itself.
The number of proper subsets of the set A = {1, 2, 3} is ___.