From UML2.1.2:
'The ComponentRealization concept is specialized in the Components package to (optionally) define the Classifiers that realize the contract offered by a component in terms of its provided and required interfaces. The component forms an abstraction from these various Classifiers.'
Contains a proof that the sense of direction from "implementing" Classifiers to "realized" Component is wrong w.r.t. the clearly stated conventions of Realization, or at best contradicatory w.r.t. the 'ComponentRealization.abstraction' attribute !
Image:
 define the Classifiers that realize the contract offered _by a component in terms of its provided and required interfaces..jpg)