## Grand canonical weight

### Set

 context $\Xi(\beta,\mu)$ … grand canonical partition function definiendum $w: \mathbb N \to {\mathbb R\times\mathbb R} \to \mathbb R$ definiendum $w_N(\beta,\mu):=\frac{1}{\Xi(\beta,\mu)}\ z(\beta,\mu)^N\cdot Z_N(\beta)$