Documentation

Linglib.Core.Discourse.ReferentialForm

Referential Form in Production #

@cite{ariel-2001} @cite{arnold-wasow-losongco-ginstrom-2000}

Speakers choose between reduced (pronoun) and full (name, description) forms when referring to discourse entities. This choice is governed by the accessibility of the referent: more accessible/predictable referents license more reduced forms (@cite{ariel-2001}).

The Accessibility Marking Scale #

The canonical referential form type is AccessibilityLevel, @cite{ariel-2001}'s 18-level ordering from least accessible (full name + modifier) to most accessible (zero/pro-drop). This replaces the earlier conflation with DefinitenessLevel — the accessibility and definiteness scales are non-monotonically related (names are less accessible than definite descriptions but more prominent for DOM), so they must be separate types. A coarsening function toDefLevel bridges to the DOM/DSM scale when needed.

This module provides the link between accessibility/predictability and referential form, connecting Phenomena/Reference/ (form choice) to Phenomena/WordOrder/ (position choice) via the shared dimension of NP weight/reduction.

source
inductive Core.Discourse.ReferentialForm.AccessibilityLevel :
Type

@cite{ariel-2001}'s Accessibility Marking Scale: a fine-grained ordering of referential form types from least to most accessible.

Each constructor represents a class of referring expressions. Speakers use more reduced forms for more accessible referents.

Instances For
    source
    instance Core.Discourse.ReferentialForm.instDecidableEqAccessibilityLevel :
    DecidableEq AccessibilityLevel
    Equations
    source
    instance Core.Discourse.ReferentialForm.instBEqAccessibilityLevel :
    BEq AccessibilityLevel
    Equations
    source
    def Core.Discourse.ReferentialForm.instBEqAccessibilityLevel.beq :
    AccessibilityLevel → AccessibilityLevel → Bool
    Equations
    Instances For
      source
      instance Core.Discourse.ReferentialForm.instReprAccessibilityLevel :
      Repr AccessibilityLevel
      Equations
      source
      def Core.Discourse.ReferentialForm.instReprAccessibilityLevel.repr :
      AccessibilityLevel → Nat → Std.Format
      Equations
      • One or more equations did not get rendered due to their size.
      Instances For
        source
        def Core.Discourse.ReferentialForm.AccessibilityLevel.rank :
        AccessibilityLevel → Nat

        Numeric rank: 0 (lowest accessibility) to 17 (highest). Higher rank = higher accessibility = more reduced form.

        Equations
        Instances For
          source
          def Core.Discourse.ReferentialForm.AccessibilityLevel.toDefLevel :
          AccessibilityLevel → Prominence.DefinitenessLevel

          Coarsening: each accessibility level maps to one of the 5 DefinitenessLevel categories used for differential argument marking. This is a many-to-one, non-monotone mapping — names are less accessible than definite descriptions but more prominent for DOM.

          Equations
          Instances For
            source
            @[reducible, inline]
            abbrev Core.Discourse.ReferentialForm.ReferentialForm :
            Type

            Referential form options for referring to a discourse entity. Uses @cite{ariel-2001}'s 18-level accessibility marking scale.

            Equations
            Instances For
              source
              theorem Core.Discourse.ReferentialForm.pronoun_more_reduced_than_name :
              AccessibilityLevel.unstressedPron.rank > AccessibilityLevel.fullName.rank

              An unstressed pronoun is more reduced than a full name.

              source
              inductive Core.Discourse.ReferentialForm.NextMentionBias :
              Type

              Next-mention bias: how likely a discourse referent is to be mentioned again in the subsequent utterance. Driven by thematic roles, coherence relations, and discourse structure.

              Instances For
                source
                instance Core.Discourse.ReferentialForm.instDecidableEqNextMentionBias :
                DecidableEq NextMentionBias
                Equations
                source
                instance Core.Discourse.ReferentialForm.instReprNextMentionBias :
                Repr NextMentionBias
                Equations
                source
                def Core.Discourse.ReferentialForm.instReprNextMentionBias.repr :
                NextMentionBias → Nat → Std.Format
                Equations
                • One or more equations did not get rendered due to their size.
                Instances For
                  source
                  def Core.Discourse.ReferentialForm.instBEqNextMentionBias.beq :
                  NextMentionBias → NextMentionBias → Bool
                  Equations
                  Instances For
                    source
                    instance Core.Discourse.ReferentialForm.instBEqNextMentionBias :
                    BEq NextMentionBias
                    Equations
                    source
                    def Core.Discourse.ReferentialForm.NextMentionBias.predictedForm :
                    NextMentionBias → ReferentialForm

                    Accessibility prediction: high next-mention bias licenses reduced referential form (unstressed pronoun); low bias requires full form (full name).

                    This is the monotone link at the heart of @cite{ariel-2001}'s Accessibility Marking Scale: more accessible referents → more reduced forms. The same relationship underlies the Probabilistic Reduction Hypothesis (more predictable → shorter/more reduced).

                    Equations
                    Instances For
                      source
                      theorem Core.Discourse.ReferentialForm.high_bias_more_reduced :
                      AccessibilityLevel.rank NextMentionBias.high.predictedForm > AccessibilityLevel.rank NextMentionBias.low.predictedForm

                      The predicted form for high-bias referents is more reduced than for low-bias referents.

                      source
                      def Core.Discourse.ReferentialForm.ReferentialForm.typicalWeight :
                      ReferentialForm → Nat

                      NP weight correlate: reduced referential forms are lighter. Approximate number of words in a typical instance of each form. This connects form selection to constituent ordering (heavy NP shift, DLM).

                      The same choice that makes a referent "more reduced" also makes it "lighter", linking @cite{ariel-2001}'s accessibility hierarchy to @cite{arnold-wasow-losongco-ginstrom-2000}'s heaviness effects.

                      Equations
                      Instances For
                        source
                        theorem Core.Discourse.ReferentialForm.pronoun_lightest :
                        ReferentialForm.typicalWeight AccessibilityLevel.unstressedPron ≤ ReferentialForm.typicalWeight AccessibilityLevel.shortDefDescription

                        Pronouns are at most as heavy as definite descriptions.