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Linglib.Phenomena.Morphology.Studies.BickelNichols2013

Phenomena.Morphology.Studies.BickelNichols2013 #

@cite{bickel-nichols-2013a} @cite{bickel-nichols-2013b} @cite{bickel-nichols-2013c} @cite{bickel-nichols-2001}

Cross-linguistic analyses anchored on Bickel & Nichols's WALS chapters (Ch 20 fusion, Ch 21 exponence, Ch 22 inflectional synthesis) and their 2001 paper on the orthogonality of fusion and flexivity. The 18-language MorphProfile sample is the testbed.

Bickel & Nichols's central insight #

The traditional 1D typological scale `isolating > agglutinating > fusional

polysynthetic conflates two orthogonal parameters: **fusion** (whether formatives are concatenative, nonlinear, or isolating) and **flexivity** (whether classes are predictable from form vs. arbitrary). Both "agglutinating" (concatenative + nonflexive) and "fusional" (concatenative + flexive`) are attested in the sample, demonstrating the two parameters are independent.

Contents #

Out of scope #

The substrate types (MorphProfile, Fusion, Flexivity, ...) and WALS converters live in Core/Morphology/MorphProfile.lean. Per-language B&N classification commitments (e.g., "German is fusional") live in each Fragments/{Lang}/Morph.lean as local bridge theorems. @cite{ackerman-malouf-2013}'s E-complexity / I-complexity analysis lives in Studies/AckermanMalouf2013.lean.

This file deliberately omits aggregate-count theorems (sample_X_count = N) — exact counts go stale every time a Fragment is added to the sample. The mutual-exclusion theorem MorphProfile.agglutinating_fusional_exclusive is structural and lives in Core/Morphology/MorphProfile.lean §6.

Per-language Fragment profiles, with values derived from WALS data via Core.Morphology.wals* lookup helpers. Aliases here for concise reference in theorems below.

18-language morphological sample.

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    Sentry: ISO codes are pairwise distinct across the sample. Catches accidental cross-language duplicates (two Fragments stipulating the same ISO) that per-Fragment sentries cannot see.

    @cite{bickel-nichols-2001} argue fusion and flexivity are orthogonal, and that the four cells of the (concatenative ∪ nonlinear ∪ isolating) × (flexive ∪ nonflexive ∪ none) space are independently attested. The theorems below witness the cells the sample populates.

    theorem Phenomena.Morphology.Studies.BickelNichols2013.concatenative_admits_both_flexivities :
    have concats := List.filter (fun (p : Core.Morphology.MorphProfile) => decide p.IsConcatenative) allMorphProfiles; (List.filter (fun (p : Core.Morphology.MorphProfile) => decide p.IsFlexive) concats).length > 0 (List.filter (fun (p : Core.Morphology.MorphProfile) => decide p.IsNonflexive) concats).length > 0

    Key orthogonality test: among concatenative languages, both flexive and nonflexive are attested. This refutes the traditional 1D scale's claim that fusion-axis values determine flexivity-axis values.

    Isolating cell (Mandarin, Thai) has no flexivity / no exponence marking — the B&N parameters do not apply to isolating typology.

    WALS Exponence (Ch 21A, case-specific) and B&N ExponenceScope (general) are independent: both poly+sep (Finnish, Tagalog) and mono+cum (Hindi, Georgian, Spanish) are attested in the sample.

    B&N decomposition is exhaustive on the concatenative dimension: every concatenative language in the sample is either agglutinating (concatenative + nonflexive + separative) or fusional (concatenative + flexive + cumulative).

    theorem Phenomena.Morphology.Studies.BickelNichols2013.sample_type_exhaustive :
    allMorphProfiles.length = (List.filter (fun (p : Core.Morphology.MorphProfile) => decide p.IsAgglutinating) allMorphProfiles).length + (List.filter (fun (p : Core.Morphology.MorphProfile) => decide p.IsFusional) allMorphProfiles).length + (List.filter (fun (p : Core.Morphology.MorphProfile) => decide p.IsNonlinear) allMorphProfiles).length + (List.filter (fun (p : Core.Morphology.MorphProfile) => decide p.IsIsolating) allMorphProfiles).length

    Sample partition: every language falls into exactly one of agglutinating / fusional / nonlinear / isolating. The disjointness half lives in Core/Morphology/MorphProfile.lean §6 as a structural theorem (MorphProfile.agglutinating_fusional_exclusive); this is the empirical claim that the four cells exhaust the sample.