What do you think about Kevin S. Van Horn’s formulation of probability as extended logic? It looks interesting because it doesn’t seem to rely on the not-so-intuitive Universality axiom, removing which leads to Halpern’s counter-example, or conventions, axioms/desiderata which are not required by common sense, like representing plausibility using real numbers. Even David Chapman, who is highly critical of probability theory as extended logic, seems to be okay with it. Is it widely accepted or does it have conceptual issues like the original formulation?