Selective Opacity @cite{keine-2019} #
Selective Opacity. Linguistic Inquiry 50(1), 13–62.
Summary #
@cite{keine-2019} argues that selective opacity — where the same domain is opaque to some operations but transparent to others — is a property of probes, not of domains. The constraint targets Agree, the operation underlying both movement and φ-agreement. Different probes have different horizons (categories that terminate their search), and the interplay of probe location and horizon setting produces the observed selective opacity patterns.
Core Contributions Formalized #
The transparency table (58): four operations (φ-agreement, A-movement, wh-licensing, Ā-movement) × three clause sizes (CP, TP, vP) yield a non-binary opacity pattern.
Upward Entailment (40): if a clause is opaque to a probe, all larger clauses are too.
Height-Locality Connection (33/62): the higher a probe sits in the clausal spine, the more structures are transparent to it.
Hindi LDA generalizations:
- (21): A-movement of any element renders the embedded clause obligatorily transparent for LDA
- (23): finite clauses are opaque to A-movement and φ-agreement but not Ā-movement
- (25): the transparency/opacity table by clause type and operation
Relationship to @cite{keine-2020} #
This article's simplified fValue model (transparentTo) treats clause
types as linearly ordered. @cite{keine-2020} introduces bilateral labeling
(transparentToLabel) which correctly handles partially ordered clause
types (NmlzP vs CP in Hindi). The article probes remain useful for
verifying the paper's original predictions, but the book's model
supersedes the fValue approximation. See Keine2020.lean for the
book's 4×4 transparency tables and bilateral-labeling theorems.
Key refinements in @cite{keine-2020}:
- Hindi φ/A horizon refined from ⊣ C to ⊣ T (book (219))
- Hindi Ā horizon specified as ⊣ Nmlz (not just "no horizon")
- English Ā has ⊣ C (the article treated it as horizonless)
- German adds ForceP as a distinct clause size above CP
- Vacuous probes derived from bilateral labeling (§3.5)
- HLT (279) derived as emergent property, not stipulated
Architecture #
The theory-layer infrastructure (ProbeProfile, transparentTo,
transparentToLabel, upward_entailment, height_locality_connection)
lives in Theories/Syntax/Minimalism/Probe.lean. This file
imports those definitions and verifies the paper's empirical predictions
as concrete theorems using the simplified fValue model.
Table (58): Transparency (✓) and opacity (*) by clause type and operation #
| Operation | Probe location | CP (finite) | TP (nonfinite) | vP (nonfinite) |
|---|---|---|---|---|
| φ-agreement | T⁰ | * | * | ✓ |
| A-movement | T⁰ | * | * | ✓ |
| wh-licensing | C⁰ | * | ✓ | ✓ |
| Ā-movement | C⁰ | ✓ | ✓ | ✓ |
The table captures the central empirical discovery: selective opacity is not a binary phenomenon. There are at least three distinct locality types, corresponding to different probe–horizon pairings.
Generalization (21): A-extraction renders clause transparent for LDA #
If A-movement of any element out of an embedded clause has applied, that clause is obligatorily transparent for LDA. Agreement is hence obligatory and default agreement is impossible, regardless of whether the agreement controller moves or not. Ā-movement has no such effect.
This is captured by the shared locality of A-movement and φ-agreement: both are probes on T⁰ with horizon C. If A-movement can penetrate a clause (= clause is transparent to the A-probe), φ-agreement can too.
A-movement and φ-agreement share the same horizon and probe location. This is the structural reason A-extraction entails LDA transparency: whatever is transparent to [•A•] is transparent to [φ].
Consequence: for any clause head, A-transparency implies φ-transparency. This derives generalization (21) — if A-movement can enter a clause, φ-agreement can too, making LDA obligatory.
Generalization (23): finite clauses are selectively opaque #
Finite clauses (CP) are opaque to A-movement and φ-agreement, but transparent to Ā-movement. This is a direct consequence of the probe–horizon pairings: A-probes and φ-probes have C as their horizon, so CP blocks them. Ā-probes have no horizon, so nothing blocks them.
The full (23): CP is selectively opaque — blocks A-movement and φ-agreement but not Ā-movement.
Generalization (33)/(62): Height-Locality Connection #
The higher the structural position of a probe, the more kinds of structures it can search into.
This is verified concretely: the Ā-probe (on C⁰, fValue 6) can search
into strictly more clause types than the A-probe (on T⁰, fValue 2).
The Height-Locality Connection is not a stipulation — it is derived as
a theorem in Agree.lean from the monotonicity of horizons within
extended projections.
Ā-probes are higher than A-probes in the functional sequence.
The Ā-probe can search into everything the A-probe can, and more. For all three clause sizes, Ā-transparency ≥ A-transparency.
Generalization (40): Upward Entailment #
If a clause of a given size is opaque for a probe, all larger clauses are also opaque. Verified concretely for the A-probe: vP is transparent, TP is opaque, and CP is opaque. The transition from transparent to opaque happens once and never reverses.
A-probe: opacity increases monotonically along the functional sequence. vP (F1) ✓ → T (F2) * → C (F6) *. Once opaque, always opaque.
Clause spine integration #
The named spines from ClauseSpine.lean connect to probe transparency
via fLevel: a spine's F-level determines which probes can search into
clauses of that size.
vP-sized clauses are transparent to all four probes.
CP-sized clauses are transparent only to the Ā-probe.
TP-sized clauses are transparent to wh-licensing and Ā-movement but opaque to φ-agreement and A-movement.
English hyperraising is blocked by CP #
A-movement (hyperraising) out of a finite clause is impossible in
English because the A-probe ([•A•] on T⁰) has C as its horizon.
The CP boundary blocks the A-probe's search, ruling out
*John seems [CP t likes oatmeal].
Hyperraising blocked: A-probe cannot search into CP.
Ā-extraction is fine: Ā-probe has no horizon blocking CP.
Who do you think [CP t eats oatmeal]? is grammatical.