Discussion about Warren-Cowely Parameter

The Warren-Cowely Parameter (WCP) for short range solution order is defined as:  

$$\mathrm{WCP}\_{ij} = 1 - \frac{Z\_{ij}}{x\_j \cdot Z\_i}$$ 


where $Z\_{ij}$ is the **partial** Coordination Number (CN) of j atoms around i, $Z\_{i}$ is the **total** CN around i, and $ x\_{j}$ is the nominal composition of j.


Consider a two component solution of $\ce{A}$ and $\ce{B}$. If $\mathrm{WCP}>0$, like neighbors are preferred, If $\mathrm{WCP}<0$, unlike neighbors are preferred. 


If both of $\mathrm{WCP}\_{AA}$ and $\mathrm{WCP}\_{BB}$ are positive, which one is preferred? 


