PTS Constraints #
A constraint on the Perfect Time Span. Adverbials restrict which PTS intervals are admissible.
Equations
- Tense.TemporalAdverbials.PTSConstraint Time = (NonemptyInterval Time → Prop)
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[IAI01] adverbial type classification.
durative: specifies the left boundary (e.g., "since Monday")inclusive: does not specify the left boundary (e.g., "before Monday")
- durative : AdverbialType
- inclusive : AdverbialType
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Equations
- Tense.TemporalAdverbials.instDecidableEqAdverbialType x✝ y✝ = if h : x✝.ctorIdx = y✝.ctorIdx then isTrue ⋯ else isFalse ⋯
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- One or more equations did not get rendered due to their size.
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Concrete Adverbials #
"ever since t₀": PTS must start at t₀. E.g., "has been running since Monday" → PTS.fst = Monday.
Equations
- Tense.TemporalAdverbials.everSince t₀ pts = (pts.toProd.1 = t₀)
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"for (duration) from tStart": PTS must start at tStart. Simplified duration adverbial — the duration is implicit in the interval length [tStart, RB].
Equations
- Tense.TemporalAdverbials.forDurationFrom tStart pts = (pts.toProd.1 = tStart)
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"always" / no temporal adverbial: no constraint on PTS.
Equations
- Tense.TemporalAdverbials.always x✝ = True
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"before t" (inclusive adverbial): no constraint on PTS start. The adverbial constrains the event location, not the PTS boundary.
Equations
- Tense.TemporalAdverbials.before x✝ = True
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LB Domain Extraction #
Convert a PTS constraint to a domain of compatible LB values, given that the right boundary is fixed at tc.
For a constraint C, the compatible LBs are those tLB ≤ tc such that C holds of the interval [tLB, tc].
Equations
- adv.toLBDomain tc = {tLB : Time | tLB ≤ tc ∧ ∀ (h : tLB ≤ tc), adv { fst := tLB, snd := tc, fst_le_snd := h }}
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PERF with Adverbial #
Perfect with adverbial constraint: PERF_ADV(p, adv). Combines PERF with an adverbial constraint on the PTS. Equivalent to PERF_XN with the adverbial's derived LB domain.
Equations
- Tense.TemporalAdverbials.PERF_ADV p adv s = ∃ (pts : NonemptyInterval Time), Semantics.Aspect.RB pts s.time ∧ adv pts ∧ p s.world pts
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Adverbial Type Properties #
Does this adverbial type specify the left boundary? Durative adverbials pin the LB; inclusive adverbials leave it free.
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Bridge Theorems #
PERF_ADV is equivalent to PERF_XN with the adverbial's derived LB domain.
Proof sketch: Both existentially quantify over a PTS with RB = tc. PERF_ADV requires adv(PTS); PERF_XN requires LB(tLB, PTS) with tLB ∈ toLBDomain(adv, tc). These are equivalent by definition of toLBDomain: tLB ∈ toLBDomain ↔ tLB ≤ tc ∧ adv([tLB, tc]).
"ever since t₀" specifies the LB domain to exactly {t₀} (assuming t₀ ≤ tc).
Proof sketch: toLBDomain(everSince t₀, tc) = {tLB | tLB ≤ tc ∧ tLB = t₀} = {t₀} when t₀ ≤ tc.
"before" imposes no LB constraint: all tLB ≤ tc are compatible.
Proof sketch: toLBDomain(before, tc) = {tLB | tLB ≤ tc ∧ True} = {tLB | tLB ≤ tc}.
Durative adverbials (specified LB) license U-perf → simple present.
When the LB is pinned (durative adverbial), the U-perf reading
entails the simple present via u_perf_entails_simple_present.
Inclusive adverbials (unspecified LB) yield U-perf ↔ simple present when the LB domain is maximal.
With no LB constraint, the domain is {tLB | tLB ≤ tc}. Under IMPF
(subinterval property), this is close to Set.univ for the relevant
range, so U-perf ↔ simple present by broad_focus_equiv's argument.