Documentation

Linglib.Phenomena.Complementation.Studies.TheilerRoelofsenAloni2018

Theiler, Roelofsen & Aloni (2018) — A Uniform Semantics for Declarative and Interrogative Complements #

@cite{theiler-etal-2018}

Journal of Semantics 35(3): 409–466, doi:10.1093/jos/ffy003.

This study formalizes Section 2 of the paper (semantic framework: inquisitive sentence meanings) plus the forcing mention-some example from Section 3.1, which justifies the existence of Core/Question/Basic.lean as a sibling structure to Setoid W.

What this file establishes #

  1. Figure 2 examples (Section 2.1, p. 415): the polar interrogative Did Amy leave? and the declarative Amy left. constructed via the polar and declarative constructors of Question. We prove the four characteristic properties from the paper's prose discussion (Section 2.2):

    • amyLeft is informative and non-inquisitive (declarative).
    • didAmyLeave is non-informative and inquisitive (polar question).
  2. Mention-some forcing (Section 3.1, ex. (13)): the Janna knows where one can buy an Italian newspaper scenario adapted from @cite{george-2011} requires alternatives that overlap (a world where two stores both sell Italian newspapers belongs to multiple alternatives). We construct a minimal mentionSome inquisitive content and prove mentionSome_not_partition_derived: no Setoid W produces this content via fromSetoid.

    This is the forcing theorem for the architectural decision in the "Architectural note" docstring of Core/Mood/POSWQ.lean (added 0.229.922) — it shows that Setoid → Question is a strictly weaker representation, and so the sibling-structure architecture is necessary rather than redundant.

Scope #

This file does not formalize the rest of the paper:

The point of this file is the existence theorem for the "more expressive than partitions" claim, which is what the Core/Question/Basic.lean/Core/Mood/PartitionAsInquiry.lean pair was built to support.

Section 2.1: Figure 2 — Did Amy leave? / Amy left. #

@[reducible, inline]

Worlds: 0, 1 are worlds where Amy left; 2, 3 are worlds where Amy didn't leave. Following @cite{theiler-etal-2018} Figure 2 (w₁, w₂ = Amy left, w₃, w₄ = Amy didn't leave).

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    The proposition Amy left — true at worlds w₁, w₂ (= 0, 1).

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      Figure 2(b): Amy left is informative — its informative content excludes the worlds where Amy didn't leave.

      Figure 2(b): Amy left is non-inquisitive — declaratives never raise an issue beyond what they assert.

      Figure 2(a): Did Amy leave? is non-informative — its informative content covers all worlds (the speaker rules nothing out by asking).

      Figure 2(a): Did Amy leave? is inquisitive — it has two alternatives (amyLeft and amyLeftᶜ), neither of which alone covers the universe.

      Mention-some readings force overlapping alternatives #

      The Janna/Rupert scenario from @cite{george-2011} (cited in @cite{theiler-etal-2018} ex. (13)): there are stores Newstopia, Paperworld, and Cellulose City; Newstopia and Paperworld sell Italian newspapers, Cellulose City does not. Janna knows where one can buy an Italian newspaper under a mention-some reading is true if Janna knows of any one such store. Critically, in worlds where multiple stores sell, those worlds belong to multiple alternatives (one per store) — the alternatives overlap.

      The structural feature — non-disjoint alternatives — is what @cite{theiler-etal-2018} §2 (Figure 5(b), the non-exhaustive Who left?) and the broader inquisitive-semantics tradition (e.g., @cite{ciardelli-groenendijk-roelofsen-2018}) use to motivate the move beyond partition theory. We model the irreducible structural feature with three worlds and two overlapping alternatives. The forcing theorem mentionSome_not_partition_derived shows that no Setoid on these three worlds can generate this content via fromSetoid.

      @[reducible, inline]

      World universe for the mention-some example: three worlds.

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        Alternative 1: Newstopia sells Italian newspapers — true in worlds 0 and 1.

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          Alternative 2: Paperworld sells Italian newspapers — true in worlds 1 and 2. World 1 is where both stores sell, so it sits in both alternatives — this is the structural feature that a Setoid cannot represent.

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            The mention-some inquisitive content for where one can buy an Italian newspaper: a state resolves the issue iff every world in it agrees on at least one of the two stores selling. The alternatives are msNewstopia and msPaperworld, which overlap at world 1.

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            • One or more equations did not get rendered due to their size.
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              Forcing theorem (the architectural justification for Question). The mention-some content is not in the image of fromSetoid for any Setoid on the three worlds.

              Proof: msNewstopia = {0, 1} and msPaperworld = {1, 2} both lie in mentionSome.props. If fromSetoid r = mentionSome, each must be contained in some equivalence class of r. Since both contain world 1, those classes coincide; so worlds 0, 1, and 2 all lie in one class. Then {0, 2} is also in (fromSetoid r).props = mentionSome.props, but {0, 2} is not a subset of msNewstopia (missing 2) nor of msPaperworld (missing 0) — contradiction.

              This is the standard partition-theory limitation that motivates inquisitive semantics' move to non-disjoint alternatives (@cite{ciardelli-groenendijk-roelofsen-2018}; @cite{theiler-etal-2018} §2 Figure 5(b)).