Word-meaning and sentence-internal presupposition

The German causal preposition durch ('by', 'through') poses a challenge to formal-semantic analyses applying strict compositionality. To deal with this challenge, a formalism which builds on recent important developments in Discourse Representation Theory is developed, including a more elaborate analysis of presuppositional phenomena as well as the integration into the theory of unification as a mode of composition. It is argued that that the observed unificational phenomena belong in the realm of pragmatics, providing an argument for presuppositional phenomena at a sentence- and word-internal level.