[1] A very similar theory was developed independently by Irene Heim in 1982, under the name of File Change Semantics (FCS).
[2] Discourse representation theories have been used to implement semantic parsers[3] and natural language understanding systems.
In traditional natural language semantics, only individual sentences are examined, but the context of a dialogue plays a role in meaning as well.
DRT avoids this problem by assuming that indefinites introduce discourse referents (DRs), which are stored in the mental representation and are accessible (or not, depending on the conditions) to expressions like pronouns and other anaphoric elements.
This larger structure can be the top-level DRS or some sub-DRS according to the sentence-internal environment of the analyzed noun phrase—in other words, a level that is accessible to an anaphor that comes later.