 A basic modal probability logic adds to propositional logic formulas of the form \(P (\phi)\ge q\), where \(q\) is typically a rational number, and \(\phi\) is any formula of the language, possibly a probability formula. The reading of such a formula is that the probability of \(\phi\) is at least \(q\). This general reading of the formula does not reflect any difference between modal probability logic and other probability logics with the same formula; where the difference lies is in the ability to embed probabilities in the arguments of probability terms and in the semantics. The following subsections provide an overview of the variations of how modal probability logic is modeled. In one case the language is altered slightly   (Section 4.2), and in other cases, the logic is extended to address interactions between qualitative and quantitative uncertainty   (Section 4.4) or dynamics   (Section 4.5).