Before revision:  This is consistent with the perspective that the proof of work must cost a sizable fraction of the value that can be transferred through the network in order to keep the Blockchain system secure from double spending attacks .
After revision:  This is consistent with the perspective that , in order to keep a the Blockchain system secure from double spending attacks, the proof or work must cost a sizable fraction of the value that can be transferred through the network in order to keep the Blockchain system secure from double spending attacks .