### How th work with enumerable and infinite set

Hello,

I am trying to do following:
Set B is the difference between QQ and the set of the prime numbers.
B is a enumerable and infinite set.
In Sage I put in the cells following expressions:

X = Set(QQ)
Y = Set(Primes())
B=Set(X.difference(Y))
B.cardinality()

then I press evaluate.
I am expecting that teh cardinality of B is +Infinity.

But Sage does not bring any result.

I tried this also initializing B like
B = InfiniteEnumeratedSets(RR).

Could anybody please give me a hint what I am doing wrong?

Thank you very much and regards.

vbk