These “four unions” are envisaged to mesh and engage with each other, like cogwheels in a mechanical apparatus. Think of a finely crafted automatic watch: the spin of one wheel sets the others in motion. Conversely, when the momentum of one decreases, that of the others follows suit.
Taken as a group, these actions have had a threefold purpose: to expand the range of institutions with access to collateralized loans from the Federal Reserve, to broaden the types of securities that can be pledged as collateral, and to lengthen the terms of the loans obtained from the Fed.