 The above two versions of Probabilism are still similar in that they both imply that any credence ought to be sharp—being an individual real number. But some Bayesians maintain that coherence does not require that much but allows credences to be unsharp in a certain sense. An even weaker version of Probabilism has been developed accordingly, defended with a Dutch Book argument that works with a more liberal conception of betting dispositions than mentioned above (Smith 1961; Walley 1991: ch. 2 and 3). See  supplement A  for some non-technical details. Bayesians actually disagree over whether coherence allows credences to be unsharp. For this debate, see the survey by Mahtani (2019) and the entry on  imprecise probabilities.