Quadratic number fields
I try to implement an inclusion test, of which I thought it must be quite simple, but until now I cannot figure out how to do it properly. Problem: Given any element x, test if x is included in some quadratic number field and return true/false. I tried the following:
x = 2 + sqrt(5) K = QuadraticField(5) print(x in K)
Here, the answer is 'no' or 'false' which is obviously wrong, so I assume I'm doing something completely wrong. What do I have to change?