Making Dynamic Semantics Explanatory: Presupposition Projection. Manuscript, Columbia University. Rothschild, D.: to appear, Presuppositions and Logical Equivalence

Understanding the pattern by which complex sentences inherit the presuppositions of their parts (presupposition projection) has been a major topic in formal pragmatics since the 1970s. Heim’s classic paper “On the Projection Problem for Presuppositions ” (1983) proposed a replacement of truth-conditional semantics with a dynamic semantics that treats meanings as instructions to update the common ground. Heim’s system predicts the basic pattern of presupposition projection quite accurately. The classic objection to this program (including other versions of dynamic semantics) is that the treatment of binary connectives is stipulative, and other, equally natural treatments fail to make the right predictions about presupposition projection. I give a variation on Heim’s system that is designed to escape this objection. I show that the most liberal possible version of this variant is equivalent to a strong-Kleene system in terms of its definedness conditions.