 With these preliminaries out of the way, we turn to the first major question: Where are presuppositions accommodated? Though it may seem odd at first, this question is inescapable if we assume, as is standard in dynamic semantics, that an expression may occur in several contexts at the same time (cf. Section 4.3). For Heim (1982), following Lewis (1979), accommodation is a process whereby contexts are adjusted so as to make update possible when presuppositions are not satisfied. In terms of her treatment of accommodation, Heim’s major innovation over Lewis was to allow this process to take place not only in the global context of utterance, but also on local contexts found midway through an update. To illustrate, consider the following: