 The I/O-logic framework has proven useful in a number of respects: it puts factual detachment where, for many, it belongs: at the very core of deontic reasoning. It allows for many fine-grained distinctions and nuanced accounts of the interplay between detachment and logical reasoning about facts and norms that seem hard to characterize in terms of classical possible worlds-semantics. Finally, it can accommodate various notions of permission and their relation to obligation (Makinson &amp; van der Torre 2003). On the downside, how to integrate a procedural semantics from I/O-logic with semantics for epistemic logics, logics of agency, and the like is far from obvious. More generally, since in I/O-logic the notion of obligation is—by definition—one of an “output”, it is unclear how, e.g., truth-functional connectives or other modal operators can be applied to statements concerning obligation (e.g., it is believed that murder is wrong and sometimes done), or what a nested statement like “it is permissible that it is obligatory that p” would mean in this  framework.[81]