I'm pretty new to complex multiplication and am struggling with Corollary 5.20 in Elliptic Curves with Complex Multiplication and the Conjecture of Birch and Swinnerton-Dyer by Rubin.
According to a comment here, we should be able to use this and know how the ray class groups are generated (torsion points). However I don't see how that is done.
I'm also not sure about the proof (which is mostly not given) and would be grateful if someone could explain it a little.