Event predicates and the Event type are imported from
Semantics/Events/Basic.lean — the unified event ontology.
Tense-aspect code uses Event Time and W → Event Time → Prop without
referencing .sort (the field exists for Krifka-style consumers but
is irrelevant for Klein-style tense composition).
Predicate over time intervals (output of IMPF/PRFV).
Equations
- Semantics.Aspect.IntervalPred W Time = (W → NonemptyInterval Time → Prop)
Instances For
Predicate over time points (output of PERF, input to TENSE).
Defined as WorldTimeIndex W Time → Prop to make the situation structure
explicit in the tense-aspect pipeline, connecting directly to
situation semantics (Elbourne, Percus, Kratzer).
Equations
- Semantics.Aspect.PointPred W Time = (Intensional.WorldTimeIndex W Time → Prop)
Instances For
Viewpoint aspect types. [Kle94] identified imperfective, perfective, perfect, and prospective. [Smi97] added the neutral viewpoint (default in the absence of overt aspect morphology).
- imperfective : ViewpointType
- perfective : ViewpointType
- perfect : ViewpointType
- prospective : ViewpointType
- neutral : ViewpointType
Instances For
Equations
- Semantics.Aspect.instDecidableEqViewpointType x✝ y✝ = if h : x✝.ctorIdx = y✝.ctorIdx then isTrue ⋯ else isFalse ⋯
Equations
Equations
- One or more equations did not get rendered due to their size.
Instances For
Equations
Bool-level viewpoint aspect, capturing the perfective/imperfective distinction
without the full interval-based Event Time → Prop/IntervalPred machinery.
Used by Modal/Ability.lean and the actuality-inference consumers
(Modality/ActualityEntailments.lean, Studies/Hacquard2006.lean)
where the key insight is simply
"perfective requires actualization, imperfective doesn't."
- perfective : ViewpointAspectB
- imperfective : ViewpointAspectB
Instances For
Equations
- Semantics.Aspect.instDecidableEqViewpointAspectB x✝ y✝ = if h : x✝.ctorIdx = y✝.ctorIdx then isTrue ⋯ else isFalse ⋯
Equations
Equations
- One or more equations did not get rendered due to their size.
Instances For
Equations
Project ViewpointType to the coarser perfective/imperfective distinction.
Returns none for perfect and prospective (neither is simply perf/impf).
Equations
- Semantics.Aspect.ViewpointType.perfective.toBoolAspect = some Semantics.Aspect.ViewpointAspectB.perfective
- Semantics.Aspect.ViewpointType.imperfective.toBoolAspect = some Semantics.Aspect.ViewpointAspectB.imperfective
- Semantics.Aspect.ViewpointType.perfect.toBoolAspect = none
- Semantics.Aspect.ViewpointType.prospective.toBoolAspect = none
- Semantics.Aspect.ViewpointType.neutral.toBoolAspect = none
Instances For
Roundtrip: embedding then projecting is the identity.
The TT↔TSit interval relation for each viewpoint ([Kle94]: 108).
Equations
- Semantics.Aspect.ViewpointType.imperfective.ttTSitRelation tt tsit = (tt < tsit)
- Semantics.Aspect.ViewpointType.perfective.ttTSitRelation tt tsit = (tsit ≤ tt)
- Semantics.Aspect.ViewpointType.perfect.ttTSitRelation tt tsit = tt.isAfter tsit
- Semantics.Aspect.ViewpointType.prospective.ttTSitRelation tt tsit = tt.isBefore tsit
- Semantics.Aspect.ViewpointType.neutral.ttTSitRelation tt tsit = tt.initialOverlap tsit
Instances For
Equations
- One or more equations did not get rendered due to their size.
Visibility properties of viewpoints #
[Smi97] §4.1 tabulates four visibility properties per viewpoint: whether
the initial point of the situation is asserted, whether the final point is
asserted, whether the viewpoint presents the situation as informationally
closed, and whether the viewpoint can focus an interval strictly inside the
situation (the structural source of the imperfective's "preliminary stages"
reading for punctuals, §4.2.2). Each property derives from ttTSitRelation:
visibility is interval geometry, and Smith's Table 1 re-emerges below as
iff theorems, not as a stipulated lookup.
The viewpoint asserts the situation's initial point: every licensed
(tt, tsit) pair has tt containing tsit.fst.
Equations
- v.ShowsInitialPoint = ∀ {Time : Type} [inst : LinearOrder Time] {tt tsit : NonemptyInterval Time}, v.ttTSitRelation tt tsit → tsit.toProd.1 ∈ tt
Instances For
The viewpoint asserts the situation's final point.
Equations
- v.ShowsFinalPoint = ∀ {Time : Type} [inst : LinearOrder Time] {tt tsit : NonemptyInterval Time}, v.ttTSitRelation tt tsit → tsit.toProd.2 ∈ tt
Instances For
The viewpoint presents the situation as informationally closed: the topic time reaches at least the situation time's right endpoint.
Equations
- v.IsClosed = ∀ {Time : Type} [inst : LinearOrder Time] {tt tsit : NonemptyInterval Time}, v.ttTSitRelation tt tsit → tsit.toProd.2 ≤ tt.toProd.2
Instances For
The viewpoint focuses a topic time strictly inside the situation, the structural source of the imperfective's "preliminary stages" reading for punctual events ([Smi97] §4.2.2).
Equations
- v.FocusesPreliminaryStages = ∀ {Time : Type} [inst : LinearOrder Time] {tt tsit : NonemptyInterval Time}, v.ttTSitRelation tt tsit → tt < tsit
Instances For
[Smi97] Table 1, IP column: only perfective and neutral assert the initial point.
[Smi97] Table 1, FP column: only perfective asserts the final point.
[Smi97] Table 1, Closed column: only perfective and perfect are closed.
[Smi97] Table 1, Preliminaries column: only the imperfective places the topic time strictly inside the situation.
IMPERFECTIVE: reference time properly contained in event runtime. [Kle94]: TT INCL TSit. [KS26] eq. 25.
Equations
- Semantics.Aspect.IMPF P w t = ∃ (e : Event Time), t < e.τ ∧ P w e
Instances For
PERFECTIVE: event runtime contained in reference time. [Kle94]: TT AT TSit (simplified to TSit ⊆ TT, following [Smi97]). [KS26] eq. 28.
Equations
- Semantics.Aspect.PRFV P w t = ∃ (e : Event Time), e.τ ≤ t ∧ P w e
Instances For
PROSPECTIVE: reference time before situation time. [Kle94]: TT BEFORE TSit.
Equations
- Semantics.Aspect.PROSP P w t = ∃ (e : Event Time), t.isBefore e.τ ∧ P w e
Instances For
INIT_OVERLAP: initial overlap between reference time and event runtime. [Pan03] eq. 7b: ⟦NEUTRAL⟧ = λP.λi.∃e[i ∂τ(e) & P(e)] The beginning of the eventuality is in the reference interval, but the end may extend beyond. Derives experiential perfect readings.
Renamed from NEUTRAL to avoid collision with [Smi97]'s
neutral viewpoint (ViewpointType.neutral), which is a different concept.
Pancheva's operator is an inner Asp₂ head; Smith's neutral viewpoint is
a default viewpoint type.
Equations
- Semantics.Aspect.INIT_OVERLAP P w t = ∃ (e : Event Time), t.initialOverlap e.τ ∧ P w e
Instances For
Right Boundary: PTS finishes at reference time point t.
Equations
- Semantics.Aspect.RB pts t = (pts.toProd.2 = t)
Instances For
Left Boundary: PTS starts at time tLB.
Equations
- Semantics.Aspect.LB tLB pts = (pts.toProd.1 = tLB)
Instances For
PERFECT: introduces Perfect Time Span. [KS26] eq. 22b — the standard XN-theoretic entry that K&S start from. Verified against the proceedings PDF.
K&S notation: λp_it.λt.∃t_PTS.[RB(t_PTS, t) ∧ p(t)]. The p(t) is
written by K&S as application to the outer reference time, with the
composition convention that t is bound to t_PTS when IMPF appears
below PERF (paper §4.2.1, sentence after eq. 25). The implementation
here applies p to pts directly (the post-composition meaning), which
matches K&S's worked composition in their (26).
Equations
- Semantics.Aspect.PERF p s = ∃ (pts : NonemptyInterval Time), Semantics.Aspect.RB pts s.time ∧ p s.world pts
Instances For
PERFECT with Extended Now (K&S's revision: domain-restricted left boundary). [KS26] eq. 23b. Verified against the proceedings PDF.
K&S notation: λp_it.λt.∃t_PTS.∃t_LB ⊆ tᵣ. [LB(t_LB, t_PTS) ∧ RB(t_PTS, t) ∧ p(t)]. The domain restriction tᵣ constrains where the
LB can be placed; narrow focus on BEEN generates alternatives over tᵣ.
K&S's (23b) is not the standard XN entry — that's their (22b),
realized here as PERF. (23b) is K&S's own revision adding an LB
existential bounded by the domain restriction. The legacy name
PERF_XN predates this clarification; both PERF and PERF_XN are
XN-theoretic, the difference being the LB+domain-restriction.
Type-level simplification: K&S's t_LB is an initial subinterval of
t_PTS (per their 23a), and t_LB ⊆ t_r compares two interval-sets.
The implementation here uses tLB : Time (a single point) with
∃ tLB ∈ tᵣ (membership), simplifying K&S's set-theoretic LB to a
single time witness inside the domain-restriction set. The simpler
typing is sufficient for the empirical predictions K&S draw and
avoids carrying intervals at every level.
Equations
- Semantics.Aspect.PERF_XN p tᵣ s = ∃ (pts : NonemptyInterval Time), ∃ tLB ∈ tᵣ, Semantics.Aspect.LB tLB pts ∧ Semantics.Aspect.RB pts s.time ∧ p s.world pts
Instances For
IMPF matches Klein's IMPERFECTIVE: ∃e where TT ⊂ TSit.
PRFV matches Klein's PERFECTIVE: ∃e where TSit ⊆ TT.
PERF(IMPF(P)) unfolds: ∃ PTS and event, with PTS right-bounded at t, the PTS properly inside the event, and P holds of the event.
PERF(PRFV(P)) unfolds: ∃ PTS and event, with PTS right-bounded at t, the event inside the PTS, and P holds of the event.
Narrower domain restriction is stronger (monotone in tᵣ).
PERF is monotone: p ⊆ q → PERF(p) ⊆ PERF(q).
IMPF and PRFV impose opposite containment directions. IMPF: reference ⊂ event runtime. PRFV: event runtime ⊆ reference.
[Pan03] decomposes perfect participles into two aspect heads: [T [Asp₁=PERFECT [Asp₂=VIEWPOINT [vP]]]]. The inner Asp₂ (UNBOUNDED, INIT_OVERLAP, or BOUNDED) determines the perfect type (universal, experiential, or resultative). The outer Asp₁ = PERFECT introduces the PTS via a final subinterval relation rather than a point-based right boundary.
Pancheva's UNBOUNDED (Asp₂): non-strict ⊆ variant of IMPF. ⟦UNBOUNDED⟧ = λP.λi.∃e[i ⊆ τ(e) & P(e)] ([Pan03]: 282, eq. 7b). Differs from IMPF in using non-strict ⊆ rather than strict ⊂.
Equations
- Semantics.Aspect.UNBOUNDED P w t = ∃ (e : Event Time), t ≤ e.τ ∧ P w e
Instances For
Pancheva's BOUNDED (Asp₂): strict ⊂ variant of PRFV. ⟦BOUNDED⟧ = λP.λi.∃e[τ(e) ⊂ i & P(e)] ([Pan03]: 282, eq. 7b). Differs from PRFV in using strict ⊂ rather than non-strict ⊆.
Equations
- Semantics.Aspect.BOUNDED P w t = ∃ (e : Event Time), e.τ < t ∧ P w e
Instances For
Pancheva-style interval-level PERFECT (Asp₁). ⟦PERFECT⟧ = λp.λi.∃i'[PTS(i', i) & p(i')] ([Pan03]: 284, eq. 9b). PTS(i', i) iff i is a final subinterval of i': i ⊆ i' ∧ i.snd = i'.snd.
Equations
- Semantics.Aspect.PERF_P p w i = ∃ (pts : NonemptyInterval Time), i.finalSubinterval pts ∧ p w pts
Instances For
Point-based PERF is the special case of interval-based PERF_P where the reference interval degenerates to a point [t, t].
PERF_P is monotone: if p entails q, then PERF_P(p) entails PERF_P(q).
[Pan03] perfect type classification. The embedded Asp₂ determines the perfect reading:
- universal = PERFECT(UNBOUNDED): event ongoing throughout PTS
- experiential = PERFECT(NEUTRAL): event began within PTS
- resultative = PERFECT(BOUNDED): event completed within PTS Note: Pancheva's resultative properly involves a result state relation; BOUNDED is a simplification sufficient for the temporal structure.
- universal : PerfectType
- experiential : PerfectType
- resultative : PerfectType
Instances For
Equations
- Semantics.Aspect.instDecidableEqPerfectType x✝ y✝ = if h : x✝.ctorIdx = y✝.ctorIdx then isTrue ⋯ else isFalse ⋯
Equations
Equations
- One or more equations did not get rendered due to their size.
Instances For
Universal perfect: PERF_P(UNBOUNDED(V)). "has been running" — event ongoing throughout PTS. [Pan03]: explains why universal reading requires imperfective.
Equations
Instances For
Experiential perfect: PERF_P(INIT_OVERLAP(V)). "has visited Paris" — event began within PTS. [Pan03]: initial-overlap aspect allows event to extend beyond PTS.
Equations
Instances For
Resultative perfect: PERF_P(BOUNDED(V)). "has broken the vase" — event completed within PTS. Simplified: properly involves result state ([Pan03]: 288).
Equations
Instances For
perfProg at a point entails universalPerfect at that point. Since IMPF (strict ⊂) entails UNBOUNDED (non-strict ⊆), PERF(IMPF(V)) entails PERF(UNBOUNDED(V)) = universalPerfect.
Evaluate an interval predicate at a point (trivial interval [t, t]). Bridge for non-perfect forms.