 In recent work, Stalnaker has enriched his notion of a context. In addition to a sets of possible worlds, he introduces (i) multiple centers within those worlds representing the participants in a conversation, and (ii) accessibility relations among the centers representing interlocutors’ ways of identifying each other (Stalnaker 2008, 2014). This added structure is intended to capture self-locating presuppositions that can help explain what’s communicated by indexical expressions like ‘I’, ‘you’ and ‘now’. For a helpful overview of the motivation for such an approach, see (Ninan 2010a) and for further development of multi-centered accounts of propositional content see (Torre 2010, Ninan 2013).