The following claim is stated on p. 155 of Manna and Pnueli's The Temporal Logic of Reactive and Concurrent Systems: Specification.
Let $P_1$ and $P_2$ be two finitely branching transition systems whose justice and compassion sets are empty, i.e., $\mathcal{J} = \mathcal{C} = \emptyset$. Then $\mathcal{R}(P_1)=\mathcal{R}(P_2)$ iff $\mathcal{F}(P_1)=\mathcal{F}(P_2)$.
Here $\mathcal{R}(P)$ is the inifinitary semantics of $P$, and $\mathcal{F}(P)$ - its finitary semantics.
The claim is stated without proof. How can it be proved? Alternatively, where can I find a proof? (I suspect the claim is taken from some paper, but no citation is given in the textbook.)