Hansson (2010) [Han10] #
Consonant Harmony: Long-Distance Interaction in Phonology. University of California Publications in Linguistics 145.
[Han10] surveys ~175 cases of long-distance consonant agreement across >130 languages, organized by harmonizing property (coronal/sibilant, dorsal, labial, secondary-articulation, nasal, liquid, stricture, laryngeal). The formal analysis is a modified Agreement-by-Correspondence model after [RW04a], with two theoretical refinements: (a) C-C correspondence is construed as directionally asymmetric (strictly anticipatory), and (b) the relevant agreement constraints are formulated as targeted constraints in the Wilson sense.
What this file formalizes (and what it does not) #
We do not formalize Hansson's correspondence apparatus, his targeted-constraint architecture, or his speech-error / palatal-bias arguments — those live in the OT layer and the speech-planning literature. What we formalize here is the surface stringset of one of the leading case studies — Navajo sibilant harmony, prominently featured in [Han10]'s introduction (§1.1) and discussed in detail in §2.4.1.1 — as a tier-based strictly 2-local language, following the subregular tradition ([McM16]).
The framing is the same as in RoseWalker2004.lean: the ABC-style
analysis derives the surface generalization; the TSL_2 description
characterizes the surface stringset. The two analyses operate at
different levels and are not in competition for the same explanatory
work.
Sibilant harmony is a symmetric dissimilation-style phonotactic — the
forbidden pair is "tier-adjacent and unequal" — so this study is the
canonical instance of the AGREE specialization in
Phonology/Subregular/Agree.lean, the non-identity dual of the
OCP ([Gol76], [McC86]). The Kikongo case in
RoseWalker2004.lean is asymmetric and instantiates the generic
forbidden-pair constructor directly rather than via AGREE.
Design boundary #
Things this formalization is silent on, by design:
- Directionality: [Han10] argues consonant harmony is strictly anticipatory (right-to-left). The TSL_2 description with symmetric forbidden pairs licenses the surface stringset regardless of which segment "triggered" the harmony — the directional derivation lives in the OT/ABC layer.
- Stem control / trigger-target asymmetry: the targeted-constraint architecture distinguishes the feature source from its target. Single-tier TSL with a fixed predicate has no notion of source vs target.
- Similarity scaling: in ABC, the CORR-C↔C constraint family is scaled by featural similarity and distance ([Han10] §4.2.1.1) — only sufficiently similar consonants enter into correspondence. The TSL_2 stringset is sharp.
- Speech-error parallels (palatal bias): [Han10]'s chapter 6 argues that consonant harmony has its roots in speech-planning errors, with the palatal bias as the central diagnostic. This is an extragrammatical claim outside any synchronic surface description.
- Similarity-graded transparency vs opacity: [Han10]'s
chapter 3 reviews cases where intervening segments behave
differently depending on how similar they are to the harmonizing
pair. Single-tier TSL with a fixed tier predicate cannot express
this — see the design-boundary docstring on
tierProjectnon-monotonicity inForbiddenPairs.lean, and the load-bearing gradient-OCP instance inStudies/FrischPierrehumbertBroe2004.lean, which formalises [FPB04]'s natural-classes similarity metric (eq. 7) and proves no similarity-threshold TSL_2 grammar can match three Table IV bins. Closely related: the autosegmental/feature-geometry tradition ([Sag86]) treats the harmonizing feature itself as a tier-resident object; that representational layer is upstream of the surface stringset characterized here.
Function-level subregular classification (cross-reference) #
The TSL_2 description here characterizes the stringset of Navajo
sibilant harmony — the language that the harmony filter accepts. The
function that maps an underlying form to its surface realization
admits a separate subregular classification per
Core/Computability/Subregular/Function/: long-distance consonant
agreement is generally Tier-Subsequential (not ISL or OSL — those
require a contiguous k-window), and per [Han10]'s
strictly-anticipatory directionality argument it is specifically
Right-Tier-Subsequential. We do not encode the function-level
classification here; the language-level TSL_2 statement is the cleaner
unit because the directionality is upstream and the surface filter is
direction-symmetric.
Navajo sibilant harmony — the leading case #
Navajo (Athapaskan; [Han10] §1.1, §2.4.1.1) has two contrasting sibilant series: an alveolar series {s, z, ts, tsʼ, dz} and a postalveolar series {ʃ, ʒ, tʃ, tʃʼ, dʒ}. A sibilant in the verb root determines the realization of all sibilants in preceding "conjunct" prefixes. For example (data from McDonough 1991, cited as Hansson's example (6)): underlying /si-dʒéːʔ/ surfaces as [ʃidʒéːʔ] 'they lie (slender stiff objects)' — the alveolar /s/ in the prefix harmonizes to the postalveolar place of the root /dʒ/; underlying /ʃ-is-ná/ surfaces as [sisná] 'he carried me' — the postalveolar /ʃ/ in the prefix harmonizes to the alveolar place of the root /s/.
The surface generalization: no two sibilants of differing place
(anterior vs posterior) may co-occur within the harmonic domain.
Equivalently, every tier-adjacent pair of sibilants must agree in
place — the TSL_2 instance of TSLGrammar.agree.
A minimal alphabet sufficient to demonstrate Navajo sibilant harmony as a TSL_2 stringset. We do not model the full Navajo inventory — just enough segment classes to distinguish the relevant natural classes (the two sibilant series, non-sibilant consonants, vowels).
- antSib : NSeg
An anterior (alveolar) sibilant: /s, z, ts, tsʼ, dz/.
- postSib : NSeg
A posterior (postalveolar) sibilant: /ʃ, ʒ, tʃ, tʃʼ, dʒ/.
- neutralC : NSeg
A non-sibilant consonant — transparent for sibilant harmony.
- vowel : NSeg
A vowel — transparent for sibilant harmony.
Instances For
Equations
- Phonology.Studies.Hansson2010.instDecidableEqNSeg x✝ y✝ = if h : x✝.ctorIdx = y✝.ctorIdx then isTrue ⋯ else isFalse ⋯
Equations
- One or more equations did not get rendered due to their size.
Instances For
Equations
NSeg's sibilant class, grounding the tier predicate in the shared
Subregular.Sibilant substrate: the two sibilant series map to anterior and
posterior, the transparent material (non-sibilant consonants, vowels) to neutral.
Equations
- Phonology.Studies.Hansson2010.NSeg.antSib.toSibilant = Subregular.Sibilant.anterior
- Phonology.Studies.Hansson2010.NSeg.postSib.toSibilant = Subregular.Sibilant.posterior
- Phonology.Studies.Hansson2010.NSeg.neutralC.toSibilant = Subregular.Sibilant.neutral
- Phonology.Studies.Hansson2010.NSeg.vowel.toSibilant = Subregular.Sibilant.neutral
Instances For
The harmonizing-class tier predicate: only sibilants project; non-sibilant
consonants and vowels are transparent (off-tier). Grounded in Sibilant.onTier
through NSeg.toSibilant rather than re-stipulated, so the tier choice — the
substantive theoretical commitment — lives in one place.
Equations
- s.onTier = s.toSibilant.onTier
Instances For
A pre-harmony underlying form analogous to /si-dʒéːʔ/: an anterior sibilant prefix preceding a postalveolar sibilant in the root, across an intervening vowel. The two disagreeing sibilants are tier-adjacent under the sibilant projection.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The post-harmony surface form analogous to [ʃidʒéːʔ]: the prefix sibilant has been realized as postalveolar to agree with the root.
Equations
- One or more equations did not get rendered due to their size.
Instances For
A control form analogous to [sisná]: only anterior sibilants in the word, with intervening vowels and a non-sibilant consonant.
Equations
- One or more equations did not get rendered due to their size.
Instances For
A control form with no sibilants at all — vacuously legal, since the tier projection is empty.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The pre-harmony underlying form is rejected: it contains a tier-adjacent disagreeing-sibilant pair.
The post-harmony surface form is accepted: every tier-adjacent sibilant pair agrees in place.
A form with only anterior sibilants is accepted — the AGREE constraint forbids disagreement, not co-occurrence.
Forms with no sibilants are vacuously accepted — the tier projection is empty, so there are no tier-adjacent pairs to check.
§ 6.1 The SP_2 formalisation of Navajo #
The same long-distance phonotactic — no anterior+posterior sibilant
co-occurrence — admits a strictly piecewise (SP_2) characterisation
that uses subsequences (non-contiguous selections) rather than tier
projection. The SP_2 grammar forbids the length-2 subsequences
[antSib, postSib] and [postSib, antSib]; intervening material is
invisible by construction (subsequences ignore position). This
naturally captures transparent harmony — exactly Navajo's profile.
[McM16] argues that consonant harmony in general requires TSL_2, not SP_2: SP cannot model blocker-style opacity (where a specific intervening consonant breaks long-distance harmony). For Navajo's transparent harmony the two classifications coincide on the surface stringset; the typological argument for TSL ⊃ SP turns on opaque blockers, which are unattested in Navajo — the rare opaque cases are Rwanda and Berber ([Han10] ch. 3) — and are not formalised here.
§ 6.2 Agreement on Navajo's transparent inputs #
On the canonical Navajo inputs introduced in §3, the TSL_2 and SP_2
analyses make the same accept/reject prediction. The structural reason
is captured by sp_lang_of_one_sibilant_class_absent: any input
lacking either sibilant class is in the SP-harmony language, since no
length-2 sublist can be the forbidden mixed-place pair.
Structural agreement helper: any input lacking either anterior
or posterior sibilants is in the SP_2 sibilant-harmony language. The
forbidden subsequences [antSib, postSib] and [postSib, antSib] both
require both sibilant classes, so the absence of either suffices.
Pre-harmony underlying form is rejected by SP_2 too — the
mixed-place subsequence [antSib, postSib] is present at positions
0 and 2 (separated by a vowel), violating the forbidden-subsequence
ban. The witness is exhibited explicitly.
Post-harmony surface form is accepted by SP_2 too — postSib
appears but antSib does not, so the forbidden mixed-place
subsequences cannot occur. Direct corollary of the structural helper.
Only-anterior control is accepted by SP_2 too — symmetrically,
antSib appears but postSib does not.
No-sibilant control is accepted by SP_2 too — the input has neither sibilant class, so the structural helper applies trivially.