To compute the abstract class group I can just create a number field
K = QuadraticField(-23)
and ask for it
K.class_group()
 -> Multiplicative Abelian Group isomorphic to C3
Is there a way to obtain representatives of the ideal classes (like in
Magma where there is a second return value that is a map from the
abstract group to the set of prime ideals?
When trying to obtain generators "by hand" I encountered the following
problem:
p = K.factor_integer(2)[0][0]
is a prime divisor of 2, which happens to have order 3 (the function
p.order() is not implemented yet).
p.is_principal()
 -> False
However:
(p^3).is_principal()
 -> False
gives the wrong answer.
This roundabout gives the correct answer
len((p^3).gens_reduced()) == 1
 -> True
but I encountered instances where the reduced set of generators is not
as reduced as it could be, so this is not a reliable method.


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