  W-States have achieved the status of the standard fully symmetric entangled
states, for many entanglement application purposes. Z-States are a
generalization of W-States that display an elegant algebra, enabling short
paths to desired results. This paper describes Z-States algebra starting from
neat definitions and laying down explicitly some fundamental theorems on
composition and distillation, needed for applications. These theorems are
synthesized into a generic tunable Entanglement-Distillation Protocol.
Applications are readily developed based upon the tunable protocol. A few
examples are provided to illustrate the approach generality. A concomitant
graphical representation allows fast comprehension of the protocol inputs,
operations and outcomes.
