| context | $ \Delta \in \mathbb R_+ $ |
| definiendum | $ \langle \mathcal M, H,{\hat\rho}\rangle \in \mathrm{it} $ |
| postulate | $\langle \mathcal M, H,{\hat\rho}\rangle$ … classical statistical ensemble |
| postulate | $\hat\rho: \mathbb R_+\to(\Gamma_{\mathcal M} \to\mathbb R_+) $ |
| postulate | $\hat\rho(E;{\bf q},{\bf p}):=\begin{cases} 1 & \mathrm{if}\ E\le H({\bf q},{\bf p})\le E+\Delta \\\\ 0 & \mathrm{else} \end{cases}$ |
Wikipedia: Microcanonical ensemble