Is `Axxphi` the empty set or not, where `phi` denotes the empty set and A is any set?

The set of odd prime numbers is the empty set.

The cardinal number of the empty set is

Which of the following is the empty set

Which of the following is the empty set?

if A ={phi ,{phi}}, then the power set of A is

IF A any set, then A sub A .

Which of the following sets of real numbers is such that if x is an element of the set and y is an element of the set, then the sum of x and y is an element of the set ? I. The set of negative integers II. The set of rational numbers III. The set of irrational numbers

Let A be any non-empty set. Then, prove that the identity function on set A is a bijection.

Let A be any non-empty set. Then, prove that the identity function on set A is a bijection.

Given a non -empty set X, let **: P(X) xx P(X) ->P(X) be defined as A **B = (A - B) uu(B - A), AAA , B in P(X) . Show that the empty set varphi is the identity for the operation ** and all the elements A of P(A) are invertible with A^-1 =A