 is an elliptic curve with conductor
 is an elliptic curve with conductor  ,
and fix a prime
,
and fix a prime  such that
 such that 
 is surjective.
Fix a quadratic imaginary field
 is surjective.
Fix a quadratic imaginary field  that satisfies the Heegner
hypothesis for
 that satisfies the Heegner
hypothesis for  . For any prime
. For any prime  satisfying the
conditions of [Rub89, Prop. 5], let
 satisfying the
conditions of [Rub89, Prop. 5], let 
![$ c_{p} \in \H ^1(\mathbb{Q},E)[\ell]$](img582.png) be the corresponding Kolyvagin
cohomology class.
There are two natural homomorphisms
 be the corresponding Kolyvagin
cohomology class.
There are two natural homomorphisms
 .
When is
.
When is 
 
When is
