How th work with enumerable and infinite set
I am trying to do following: construct the set B that is the difference between QQ and the set of the prime numbers (note that B is a countable set). Within Sage, I tried the following
X = Set(QQ) Y = Set(Primes()) B = Set(X.difference(Y)) B.cardinality()
then I press evaluate. I am expecting that the 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.