Dynamic Modal Predicate Logic

this paper is to combine within the same logic the dynamic account of variable binding from Groenendijk and Stokhof (1991a) with the dynamic account of epistemic updating from Veltman (1991), thus combining the useful features of Dynamic Predicate Logic (DPL) with those of Update Logic (UL). At the end of the paper we will briefly look at further extensions along other score-keeping dimensions. The DPL features provide a compositional treatment of anaphoric binding, while UL provides us with a treatment of epistemic modalities. By combining the two, our logic provides a suitable framework for the representation of natural language texts involving unbound anaphora and epistemic operators, and the interplay between those. Consider the following example texts. A man walked out. Maybe he was angry. (1) If a man walks out, then maybe he is angry. (2) The semantic analysis of these example texts poses a combination of two problems. The pronoun `he' must be linked to its antecedent; in the first example this is difficult because the antecedent is in a different sentence, while the second example poses the problem of getting the universal reading for the antecedent together with the intended anaphoric link. The adverb `maybe' intuitively acts as a consistency check on the piece of discourse that it has scope over. Its use in the two example texts above makes intuitive sense, but the next example illustrates that it can also serve to rule out anaphoric links. Maybe a man walked out