Discourse Representation Theory (DRT) is a framework proposed by Hans Kamp with the objective to capture the meanings of texts, in particular addressing context-sensitive phenomena like pronouns, presupposition, and tense. The central component of DRT is the meaning representation: DRS, Discourse Representation Structure. DRS has a dual purpose: (1) to capture the meaning of the text that is processed so far; and (2) to provide the context for interpreting new sentences: the structure of DRS constrains the way contextual expressions are analysed.
There are many different variations of DRS. In the PMB we adopt the central ideas of DRT, but there are notable differences with Kamp's original proposal (and that found in the textbook by Hans Kamp and Uwe Reyle): (1) in the PMB we follow the neo-Davidsonian analysis of events, using thematic roles to connect events and states with their participants; (2) in the PMB we use predicate symbols based on WordNet synsets, rather than predicates based on word lemmas; (3) in the PMB we don't have explicit DRS-conditions for implications; instead we rewrite implications to a logically equivalent expression using negation.