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Linglib.Phenomena.Gradability.Studies.RudolphKocurek2024

@cite{rudolph-kocurek-2024}: Metalinguistic Gradability #

@cite{rudolph-kocurek-2024}

Rachel Etta Rudolph & Alexander W. Kocurek. 2024. Metalinguistic gradability. Semantics & Pragmatics 17, Article 7: 1-58.

Overview #

Finite model verification of the semantic expressivist framework for metalinguistic comparatives ("Ann is more a linguist than a philosopher"), equatives, degree modifiers, and conditionals. Verifies the paper's entailment predictions (§4.4), assertoric content (§3.3), nonclassicality of acceptance-preservation (§4.4), degree modifiers very/sorta/ mostly (§6.1), metalinguistic conditionals (§6.3), the No Reversal bridge to delineation comparatives (§7), and the revised semantics for ME transitivity (Supplement §B).

Models #

Model 1 (3 interpretations, linear order i₀ < i₁ < i₂):

Captures "Ann is more a linguist than a philosopher": at i₂ (top-ranked), both hold, and the (La∧¬Pa)-witness i₁ outranks the (Pa∧¬La)-witness i₀.

Model 2 (2 interpretations, tied j₀ ≡ j₁):

Witnesses borderline cases, equative satisfaction, and nonclassicality of acceptance-preservation (parallels informational entailment for epistemic modals, @cite{yalcin-2007}).

Model 3 (3 interpretations, linear i₀ < i₁ < i₂, two entities):

Satisfies No Reversal for tall: extensions are monotonically nested. Demonstrates that under NR, the MC simplifies to the delineation comparative (§7). A counterexample model violating NR shows that MC and delineation diverge without this constraint.

Model 4 (4 interpretations, 3 propositions, ordering l < j ≡ k < i):

Counterexample to ME transitivity in the basic semantics (Supplement §B): La ≈ Pa and Pa ≈ Ca hold, but La ≈ Ca fails (La ≻ Ca holds vacuously). The revised semantics (evalRevised) blocks La ≻ Ca and restores transitivity.

Connections #

One world.

  • w0 : W
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      Two predicates: linguist and philosopher.

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          One entity: Ann.

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              "Ann is a linguist"

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                "Ann is a philosopher"

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                  Three interpretations: i₀ < i₁ < i₂.

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                      Linear ordering: i0 ≤ i1 ≤ i2.

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                        Interpretation function:

                        • i₀: Ann is a philosopher, not a linguist
                        • i₁: Ann is a linguist, not a philosopher
                        • i₂: Ann is both
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                          Observation 1a: MCs are consistent with truth of both constituents. At i₂, Ann is both a linguist and a philosopher, yet "Ann is more a linguist than a philosopher" is true — the (La∧¬Pa)-interpretation i₁ outranks the (Pa∧¬La)-interpretation i₀.

                          The MC is also true at i₁ (where Ann is a linguist but not a philosopher).

                          The MC is false at i₀ (no (La∧¬Pa)-witness at or below i₀).

                          (f) Irreflexivity: ⊨ ¬(A ≻ A). No sentence is more the case than itself.

                          Two interpretations for borderline / nonclassicality witnesses.

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                              Tied ordering: j0 ≡ j1 (both maximal).

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                                j₀: La true, Pa false; j₁: La false, Pa true.

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                                  Observation 5: A ≈ ¬A is satisfiable (not contradictory). With tied interpretations where one makes La true and the other makes La false, "Ann is (exactly) as much a linguist as not" is coherent — it expresses a borderline case.

                                  La ≈ Pa holds on the tied model (both MCs are blocked by ties).

                                  The assertoric content of "Ann is a linguist" holds on ord₃: the top-ranked interpretation (i₂) makes La true.

                                  The assertoric content of "Ann is a philosopher" also holds on ord₃ (i₂ makes Pa true).

                                  The assertoric content of La_mc_Pa holds on ord₃: at the unique maximal interpretation i₂, the MC evaluates to true.

                                  For substantive Obs 3: i₂ is linguist only.

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                                    Nonclassicality of acceptance-preservation: (La ≻ ¬La) ∨ (¬La ≻ La) does NOT have assertoric content 1 on the tied model. At both maximal interpretations (j₀ ≡ j₁), neither direction of MC holds because the interpretations are tied.

                                    This is the key result paralleling informational entailment for epistemic modals (@cite{yalcin-2007}).

                                    Distance function for ord₃: close(i) includes interpretations at the same level or one level below.

                                    • d(i₀) = {i₀}
                                    • d(i₁) = {i₀, i₁}
                                    • d(i₂) = {i₁, i₂}
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                                      very La is true at i₂: all interpretations reasonably close to i₂ (namely i₁ and i₂) make La true.

                                      very La is false at i₁: i₀ is reasonably close to i₁ but makes La false.

                                      sorta La holds at i₁: some close interpretation (i₁ itself) makes La true, even though another close interpretation (i₀) does not.

                                      mostly La is true at i₂: there is a reasonably high level (i₁) where La is uniformly true, and the only A-false level (i₀) is below it.

                                      mostly La is false at i₁: i₀ is the only candidate level below i₁ in d(i₁), but La is false at i₀.

                                      No Reversal holds trivially on single-entity models (the antecedent e₁ ≠ e₂ can never be satisfied). For a substantive NR test, a two-entity model is needed.

                                      The key consequence of NR: when it holds, Fa ≻ Gb simplifies to the delineation comparative ∃ i' ≤ i : Fa∧¬Gb — the universal clause of eq. (48) becomes redundant. This connects metalinguistic comparatives to @cite{klein-1980}'s supervaluation comparative (see Theories/Semantics/Comparison/Delineation.lean) and @cite{kamp-1975}'s completion-based approach.

                                      Two entities for gradable adjective models.

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                                          Single predicate: tall.

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                                              NR model for "Ann is taller than Ben":

                                              • i₀: neither Ann nor Ben is tall (empty extension)
                                              • i₁: Ann is tall, Ben is not (Ann enters the extension first)
                                              • i₂: both are tall

                                              Satisfies No Reversal: extensions are monotonically nested ({} ⊆ {ann} ⊆ {ann, ben}). Uses the same 3-interpretation linear order ord₃ from Model 1.

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                                                "Ann is tall"

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                                                  "Ben is tall"

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                                                    No Reversal holds for tall on the two-entity model. Since Ann enters the extension before Ben (at i₁ vs i₂), there is no interpretation where Ben is tall but Ann is not. NR is satisfied because the extensions are monotonically nested.

                                                    Compare with nr_trivial_single_entity above, which holds vacuously on a single-entity model. Here NR constrains the relationship between two distinct entities' extensions across the ordering.

                                                    Ann is taller than Ben: the MC tall(ann) ≻ tall(ben) is true at i₁ and i₂. Witness: i₁ (Ann is tall, Ben is not).

                                                    The MC is false at i₀ (no witness: Ann is not tall at i₀).

                                                    The reverse MC — Ben taller than Ann — is false everywhere. There is no interpretation where Ben is tall but Ann is not.

                                                    Bridge: under NR, the full MC (eq. 48, with domination clause) gives the same result as the delineation comparative (eq. 128, just ∃ i' ≤ i : Fa ∧ ¬Fb, without domination clause).

                                                    NR makes clause (ii) of the MC redundant: if Fa is true and Fb is false at i, then for any i' ≤ i where Fb becomes true, Fa must also be true — so there are no (Fb∧¬Fa)-witnesses to worry about.

                                                    This connects metalinguistic comparatives to @cite{klein-1980}'s delineation comparative (see Delineation.lean).

                                                    NR-violating model: Ann and Ben "swap" across interpretations.

                                                    • i₀: Ann tall, Ben not
                                                    • i₁: Ben tall, Ann not (reversal!)
                                                    • i₂: both tall
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                                                      No Reversal fails on the violating model (for e₁=ben, e₂=ann): Ben is tall at i₁ and Ann is not, but at i₀ ≤ i₁ where Ann is tall, Ben is not — a reversal.

                                                      Without NR, MC and delineation diverge: the MC TaTb is FALSE at i₂ (the (Tb∧¬Ta)-witness i₁ outranks the (Ta∧¬Tb)-witness i₀, violating the domination clause), but the simple delineation condition (∃ Fa∧¬Fb) is TRUE (i₀ is a witness).

                                                      Reflexivity: A → A is true everywhere (every A-interpretation trivially makes A true on any ordering).

                                                      La → Pa fails at i₂ on Model 1: the La-restricted ordering ≤_{La} includes i₁ (where La is true but Pa is false), so there exists a ranked La-interpretation that does not satisfy Pa.

                                                      This shows → is NOT the material conditional — La and Pa are both true at i₂, but the conditional is false because it quantifies over all ranked La-interpretations, not just the current one.

                                                      Observation M1 (§6.3): ⊨ A → (A ≻ ¬A).

                                                      "If Pluto is a planet, then it's more a planet than not" is classically valid. On ≤_A (restricted to A-interpretations), A ≻ ¬A trivially holds: every A-interpretation makes A true, so the (A∧¬(¬A))-witness exists, and there are no (¬A∧¬A)-witnesses in the restricted ordering.

                                                      This parallels the validity of epistemic "if p then probably p" (@cite{yalcin-2007}).

                                                      M1 also holds on the tied model (Model 2), where the A-restricted ordering collapses to the single A-interpretation.

                                                      ME transitivity counterexample #

                                                      The basic semantics fails to validate ME transitivity: A ≈ B, B ≈ C ⊭ A ≈ C (Supplement §B). Model 4 provides a minimal counterexample.

                                                      Key insight: the (La∧¬Ca)-witness l has no matching (Ca∧¬La)-witness, so La ≻ Ca holds vacuously under the basic semantics. The revised semantics blocks this: l must dominate either all Ca-interpretations (i and j are above it) or all ¬La-interpretations (k is above it), and it can do neither.

                                                      Three predicates for the transitivity counterexample.

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                                                          Four interpretations for the transitivity counterexample.

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                                                              Ordering: l < j ≡ k < i (three levels). j and k are tied at the middle level — this is essential for the equatives La ≈ Pa and Pa ≈ Ca to hold (witnesses block each other).

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                                                                Interpretation function for transitivity counterexample:

                                                                • i: all three true (linguist, philosopher, psychologist)
                                                                • j: linguist and psychologist only (philosopher false)
                                                                • k: philosopher only (linguist and psychologist false)
                                                                • l: linguist and philosopher only (psychologist false)

                                                                The (La∧¬Pa)-witness j and (Pa∧¬La)-witness k are at the same level, ensuring neither MC direction holds for La vs Pa (and similarly for Pa vs Ca). But the only (La∧¬Ca)-witness is l at the bottom, with no (Ca∧¬La)-witness anywhere.

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                                                                  "Ann is a linguist" (3-predicate model)

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                                                                    "Ann is a philosopher" (3-predicate model)

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                                                                      "Ann is a psychologist"

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                                                                        A ≈ B holds: Ann is as much a linguist as a philosopher. The (La∧¬Pa)-witness j and (Pa∧¬La)-witness k are tied at the middle level, blocking both MC directions.

                                                                        B ≈ C holds: Ann is as much a philosopher as a psychologist. The (Pa∧¬Ca)-witnesses k, l and (Ca∧¬Pa)-witness j are balanced: k is tied with j, blocking both MC directions.

                                                                        A ≈ C FAILS: basic semantics predicts Ann is MORE a linguist than a psychologist. ME transitivity is violated.

                                                                        The failure mechanism: La ≻ Ca holds in the basic semantics. The (La∧¬Ca)-witness l dominates all (Ca∧¬La)-interpretations vacuously — there are none (Ca is true only at i and j, where La is also true).

                                                                        Under the revised semantics, La ≻ Ca is blocked: the (La∧¬Ca)- witness l cannot dominate all Ca-interpretations (i and j are above it) or all ¬La-interpretations (k is above it).

                                                                        ME transitivity is restored: A ≈ C holds under the revised semantics, as required by transitivity from A ≈ B and B ≈ C.

                                                                        On Model 1 (linear ordering), the revised MC agrees with the basic MC. The two diverge only when the revised semantics' stronger domination clause matters — on a linear ordering with no ties at critical levels, the basic witnesses satisfy the revised conditions too.

                                                                        Degree theory on finite models #

                                                                        Finite model verifications that the degree-theoretic formulation (Supplement §C) correctly tracks the revised semantics on Models 1–4. The key bridge theorems (Facts 9–10) are stated in MetalinguisticDegree.lean; here we verify their instances on concrete models via native_decide.

                                                                        La ≈ Ca on Model 4 (revised): denotation sets are degree-equivalent. This is the key test: ∼ transitivity gives us deg(La) = deg(Ca) even though the basic MC incorrectly predicts La ≻ Ca.