 Dynamic semantics is a suitable framework for analyzing what goes on when such sentences are interpreted, since it naturally allows the modeling of separate streams of information. For instance, AnderBois et al. 2015 provide an account of sentences like  (19)  where the matrix sentence updates a local set of possible worlds. The updated set can be seen as a potential candidate for updating the common ground with. In contrast, the appositive directly updates the common ground. Rather than a proposed common ground update, it can be seen as an imposed update (see Nouwen 2007 for an alternative dynamic logic). The ideas of AnderBois et al. 2015 are partly inspired by similar ideas that were successfully applied in the realm of evidentials; see in particular Murray 2014.