Same and different are additive presupposition triggers

We propose an account of interpretive effects involving same and different, relying on two claims: the first is that same and different are able to take scope, and the second is that they are presuppositional. On this account, same and different are decomposed into two parts: an additive operator TOO and a (non-)identity predicate. We argue that this account provides a more parsimonious account of well-known properties of same and different, such as the distinction between internal and external readings, as well as the parallelism effects discovered by Hardt and Mikkelsen (Linguist Philos 38:289-314, 2015). We also present a solution to a previously unexplained puzzle involving comparatives.