 Theorem. For each pointed plausibility model \((M,w)\), we have:    \[ \textstyle M,w\models B_a^GF \quad\text{iff}\quad \min_a(\sem{G}_M\cap\cc_a(w))\subseteq\sem{F}_M ; \]    that is, agent a believes F conditional on G at world w if and only if F is true at the most plausible G-worlds that are consistent with a’s information. 