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Linglib.Phenomena.Presupposition.Studies.Grove2022

Grove 2022: Presupposition Projection as a Scope Phenomenon #

@cite{grove-2022}

Presupposition projection as a scope phenomenon. Semantics and Pragmatics 15, Article 15: 1–39.

Core Claim #

The proviso problem — where @cite{heim-1983}'s satisfaction theory predicts weak conditional presuppositions for sentences that intuitively have unconditional ones — dissolves when presupposition projection is treated as scope-taking. Presupposition triggers have Option-typed denotations and interact with their context via monadic bind, exactly paralleling @cite{charlow-2020}'s treatment of indefinites.

Key Predictions #

For "If Theo has a brother, he'll bring his wetsuit":

The two readings are a genuine scope ambiguity, not a semantic + pragmatic strengthening. The proviso problem does not arise because the unconditional presupposition is semantically available.

Connection to @cite{heim-1992} #

For attitude verbs ("Theo believes he lost his wetsuit"), the same scope mechanism predicts:

This connects to Heim1992.lean's know/believe asymmetry but derives it from scope rather than from local-context filtering.

Empirical Data #

§1 World model #

Four worlds varying two properties: whether Theo has a brother, and whether Theo has a (unique) wetsuit.

Worlds for the conditional examples.

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      §2 The presupposition trigger #

      "His wetsuit" denotes type e_# (= Option Entity): defined when Theo has a unique wetsuit, undefined otherwise. In our simplified model, the entity is irrelevant — what matters is the definedness condition. So we model the trigger's contribution to the truth value as Option Bool: defined (with value bring(t)) when hasWetsuit, undefined otherwise.

      "his wetsuit" contributes definedness + the bring predicate.

      Modeling the trigger's contribution to the sentential truth value:

      • At worlds where Theo has a wetsuit: some (bringsWetsuit w)
      • At worlds where he doesn't: none (presupposition failure)
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        §3 Local reading (narrow scope) #

        The trigger takes scope within the consequent clause. The conditional's interpretation uses materialCond, which checks the consequent only when the antecedent is true. Result: the presupposition is conditional (hasBrotherhasWetsuit).

        Local reading of "If Theo has a brother, he'll bring his wetsuit."

        The trigger stays inside the consequent. The conditional filters: materialCond (some (hasBrother w)) (hisWetsuit w).

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          At broSuit: brother ✓, wetsuit ✓, brings ✓ → some true.

          The local reading is defined iff hasBrotherhasWetsuit.

          This is the conditional presupposition that @cite{geurts-1996} observed satisfaction accounts predict — and which Grove argues is merely one of two available readings.

          §4 Global reading (wide scope) #

          The trigger takes scope over the entire conditional via cyclic scope-taking (roll-up pied-piping). The trigger's definedness is checked first; only then does the conditional apply. Result: the presupposition is unconditional (hasWetsuit).

          Global reading: the trigger scopes over the conditional.

          hisWetsuit w >>= (λ b => materialCond (some (hasBrother w)) (some b))

          First check definedness of the trigger; then, if defined, evaluate the conditional with a fully-defined consequent.

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            At broSuit: wetsuit ✓ → defined. Brother ✓, brings ✓ → some true.

            The global reading is defined iff hasWetsuit.

            This is the unconditional presupposition that speakers actually accommodate for "If Theo has a brother, he'll bring his wetsuit." The proviso problem does not arise: this reading is semantically available without pragmatic strengthening.

            §5 Scope ambiguity = no proviso problem #

            The two readings differ only in scope. At worlds where both readings are defined, they agree on truth value — the readings differ only in their presuppositions (definedness conditions).

            Where both readings are defined, they agree on truth value.

            The global presupposition is strictly stronger than the local one: hasWetsuit → (hasBrother → hasWetsuit) but not vice versa.

            Left Identity ensures that η-shifting inside the trigger's scope and then binding is the same as not shifting at all — this is why the narrow- scope derivation is equivalent to the standard satisfaction-theory prediction (Grove fn. 13).

            §6 Attitude verb example: "Theo believes he lost his wetsuit" #

            We reuse the world model from @cite{heim-1992} (AttWorld with actual and believed) and show that the scope theory derives the same empirical predictions via different machinery.

            The complement "he lost his wetsuit" as an Iₚ-typed meaning.

            Presupposes Theo has a wetsuit at the evaluation world. When defined, asserts he lost it. At believed: has wetsuit ✓, lost it ✓. At actual: no wetsuit → undefined.

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              Local reading of "Theo believes he lost his wetsuit."

              The complement stays in situ; believe quantifies over doxastic alternatives with the complement evaluated locally.

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                Local reading at actual: Theo's only belief-world is believed, where the complement is defined and true → some true.

                The local reading is always defined.

                The presupposition is that Theo believes he has a wetsuit (= the complement is defined at all doxastic alternatives). Since believed is the only belief-accessible world from either world, and the complement is defined there, this always holds. No projection to the actual world.

                Global reading: the complement scopes out.

                The complement's definedness is evaluated at the actual world (not within the scope of believe).

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                  Global reading at actual: complement is undefined → none.

                  The presupposition projects globally: Theo must actually have a wetsuit at the evaluation world.

                  The global reading is defined iff the complement is defined at the evaluation world — the presupposition projects past believe.

                  §7 Connection to @cite{heim-1992} #

                  @cite{heim-1992}'s know/believe asymmetry is derived in Heim1992.lean via local-context filtering and KD45 frame conditions. The scope theory provides an alternative explanation: the asymmetry arises because the trigger can take different scopes relative to the attitude verb.

                  The local reading corresponds to Heim's standard satisfaction-theory prediction. The global reading is what the satisfaction theory cannot derive — and what the scope theory adds.

                  The local reading's definedness matches Heim's belief-embedding prediction: the presupposition is filtered (projected into the attitude holder's beliefs, not to the actual world).

                  The global reading adds what Heim's account lacks: a reading where the presupposition projects past the attitude verb entirely.