Generalized Quantifier Definitions #
@cite{barwise-cooper-1981} @cite{keenan-stavi-1986} @cite{peters-westerstahl-2006} @cite{van-benthem-1984}
Model-agnostic property definitions, operations, and type shifts for generalized quantifier denotations.
A GQ denotation is a function (α → Prop) → (α → Prop) → Prop mapping
a restrictor and a scope to a proposition. The properties defined here
(conservativity, monotonicity, duality, intersection condition, symmetry)
are purely logical — they hold at the predicate level and require
no model infrastructure. Decidability is recovered pointwise via
[Fintype α] + [DecidablePred R] + [DecidablePred S] for the concrete
denotations defined in Semantics.Quantification.Quantifier.
The theory-specific module Semantics.Quantification.Quantifier defines
concrete denotations (every_sem, some_sem, etc.) and proves they satisfy
these properties.
Contents #
- §1 Property definitions: all predicates on GQs, grouped by source
- §2 Operations: duality, Boolean algebra, type shifts
- §3 Mathlib bridge: connection to
Monotone/Antitone
Generalized quantifier denotation: restrictor → scope → proposition.
Under the Pi-of-Prop ordering (α → Prop ordered by pointwise
implication), a GQ is just a binary relation between predicates.
Equations
- Core.Quantification.GQ α = ((α → Prop) → (α → Prop) → Prop)
Instances For
Conservativity: Q(A, B) ↔ Q(A, A ∩ B).
Only the elements of B that are also in A matter for the quantifier's truth value. Also called "lives on" (B&C) or "intersectivity". All simple (lexicalized) determiners are conservative.
Equations
- Core.Quantification.Conservative q = ∀ (R S : α → Prop), q R S ↔ q R fun (x : α) => R x ∧ S x
Instances For
Scope-upward-monotone: if B ⊆ B' and Q(A,B), then Q(A,B').
Under the Pi-of-Prop ordering this is exactly ∀ R, Monotone (q R)
(see scopeUpMono_iff_monotone). This connects to
Semantics.Entailment.Polarity.IsUpwardEntailing = Monotone.
Equations
- Core.Quantification.ScopeUpwardMono q = ∀ (R S S' : α → Prop), (∀ (x : α), S x → S' x) → q R S → q R S'
Instances For
Scope-downward-monotone: if B ⊆ B' and Q(A,B'), then Q(A,B).
Equivalent to ∀ R, Antitone (q R) (see scopeDownMono_iff_antitone).
Equations
- Core.Quantification.ScopeDownwardMono q = ∀ (R S S' : α → Prop), (∀ (x : α), S x → S' x) → q R S' → q R S
Instances For
Intersection condition: Q(A,B) depends only on A∩B. B&C §4.8, p.189.
Equations
- Core.Quantification.IntersectionCondition q = ∀ (R S R' S' : α → Prop), (∀ (x : α), R x ∧ S x ↔ R' x ∧ S' x) → (q R S ↔ q R' S')
Instances For
Symmetric: Q(A,B) ↔ Q(B,A). B&C p.210; equivalent to intersection condition by Theorem C5.
Equations
- Core.Quantification.QSymmetric q = ∀ (R S : α → Prop), q R S ↔ q S R
Instances For
Restrictor-upward-monotone (persistent): if A ⊆ A' then Q(A,B) → Q(A',B). Linked to weak determiners and there-insertion. B&C §4.9, p.193.
Equations
- Core.Quantification.RestrictorUpwardMono q = ∀ (R R' S : α → Prop), (∀ (x : α), R x → R' x) → q R S → q R' S
Instances For
Restrictor-downward-monotone (anti-persistent).
Equations
- Core.Quantification.RestrictorDownwardMono q = ∀ (R R' S : α → Prop), (∀ (x : α), R x → R' x) → q R' S → q R S
Instances For
Positive strong: Q(A,A) for all A. P&W Ch.6: "every", "most", "the".
Equations
- Core.Quantification.PositiveStrong q = ∀ (R : α → Prop), q R R
Instances For
Negative strong: ¬Q(A,A) for all A. "Neither".
Equations
- Core.Quantification.NegativeStrong q = ∀ (R : α → Prop), ¬q R R
Instances For
Extension (EXT): Q(A,B) depends only on A and B, not on the ambient
universe M. In model-theoretic GQ theory (where Q^M takes a universe),
EXT must be stated as an additional axiom. For GQ α, EXT holds
trivially since there is no universe parameter — it's a design theorem.
Significance: EXT + CONS characterize "well-behaved" determiners.
See vanBenthem_cons_ext.
Reference: Peters & Westerståhl Ch.4 Def 4.1.
Equations
- Core.Quantification.Extension _q = True
Instances For
Second conservativity: Q(A,B) ↔ Q(A∩B, B). P&W Ch.6.
Equations
- Core.Quantification.CONS2 q = ∀ (R S : α → Prop), q R S ↔ q (fun (x : α) => R x ∧ S x) S
Instances For
Existential property: Q(A,B) ↔ Q(A∩B, everything). P&W Ch.6. Characterizes determiners that are felicitous in there-sentences.
Equations
- Core.Quantification.Existential q = ∀ (R S : α → Prop), q R S ↔ q (fun (x : α) => R x ∧ S x) fun (x : α) => True
Instances For
↑_SE Mon (@cite{peters-westerstahl-2006} §5.5): Q(A,B) & A⊆A' & A\B=A'\B → Q(A',B). On the number triangle: if Q(k,m) then Q(k',m) for k' ≥ k. Enlarging A by adding elements of B preserves Q.
Equations
- Core.Quantification.UpSEMon q = ∀ (R S R' : α → Prop), (∀ (x : α), R x → R' x) → (∀ (x : α), R' x → ¬S x → R x) → q R S → q R' S
Instances For
↑_SW Mon (@cite{peters-westerstahl-2006} §5.5): Q(A,B) & A⊆A' & A∩B=A'∩B → Q(A',B). On the number triangle: if Q(k,m) then Q(k,m') for m' ≥ m. Enlarging A by adding elements outside B preserves Q. This is property (p) from P&W §5.2: half of the EXT condition.
Equations
- Core.Quantification.UpSWMon q = ∀ (R S R' : α → Prop), (∀ (x : α), R x → R' x) → (∀ (x : α), R' x → S x → R x) → q R S → q R' S
Instances For
↓_NW Mon (@cite{peters-westerstahl-2006} §5.5): Q(A,B) & A'⊆A & A\B=A'\B → Q(A',B). On the number triangle: if Q(k,m) then Q(k',m) for k' ≤ k. Shrinking A by removing elements of B preserves Q.
Equations
- Core.Quantification.DownNWMon q = ∀ (R S R' : α → Prop), (∀ (x : α), R' x → R x) → (∀ (x : α), R x → ¬S x → R' x) → q R S → q R' S
Instances For
↓_NE Mon (@cite{peters-westerstahl-2006} §5.5): Q(A,B) & A'⊆A & A∩B=A'∩B → Q(A',B). On the number triangle: if Q(k,m) then Q(k,m') for m' ≤ m. Shrinking A by removing elements outside B preserves Q.
Equations
- Core.Quantification.DownNEMon q = ∀ (R S R' : α → Prop), (∀ (x : α), R' x → R x) → (∀ (x : α), R x → S x → R' x) → q R S → q R' S
Instances For
Smooth (@cite{peters-westerstahl-2006} §5.6): Q is ↓_NE Mon and ↑_SE Mon. Smooth quantifiers are Mon↑ (Prop 9). Under ISOM, smooth quantifiers have smooth monotonicity functions f where f(n) ≤ f(n+1) ≤ f(n)+1 (Prop 10). Most natural language Mon↑ determiners are smooth: all proportional quantifiers, "some", "all", "most", etc.
Equations
Instances For
Co-smooth (@cite{peters-westerstahl-2006} §5.6): Q's inner negation is smooth. Equivalently, ↓_NW Mon and ↑_SW Mon. "no" and "fewer than half" are co-smooth.
Equations
Instances For
Left anti-additive: Q(A∪B, C) ↔ Q(A,C) ∧ Q(B,C). P&W §5.9.
Equations
- Core.Quantification.LeftAntiAdditive q = ∀ (R R' S : α → Prop), q (fun (x : α) => R x ∨ R' x) S ↔ q R S ∧ q R' S
Instances For
Right anti-additive: Q(A, B∪C) ↔ Q(A,B) ∧ Q(A,C). P&W §5.9.
Equations
- Core.Quantification.RightAntiAdditive q = ∀ (R S S' : α → Prop), (q R fun (x : α) => S x ∨ S' x) ↔ q R S ∧ q R S'
Instances For
Transitive: Q(A,B) ∧ Q(B,C) → Q(A,C). @cite{van-benthem-1984} §3.1. "all" is the prime transitive quantifier (inclusion is transitive).
Equations
- Core.Quantification.QTransitive q = ∀ (A B C : α → Prop), q A B → q B C → q A C
Instances For
Antisymmetric: Q(A,B) ∧ Q(B,A) → A = B (extensionally). @cite{van-benthem-1984} §3.1: "all" (inclusion) is antisymmetric.
Equations
- Core.Quantification.QAntisymmetric q = ∀ (A B : α → Prop), q A B → q B A → A = B
Instances For
Linear (connected): Q(A,B) ∨ Q(B,A) for all A, B. @cite{van-benthem-1984} §3.1: "not all" (non-inclusion) is linear.
Equations
- Core.Quantification.QLinear q = ∀ (A B : α → Prop), q A B ∨ q B A
Instances For
Quasi-reflexive: Q(A,B) → Q(A,A). @cite{van-benthem-1984} §3.1. "some" is quasi-reflexive: overlap implies non-emptiness.
Equations
- Core.Quantification.QuasiReflexive q = ∀ (A B : α → Prop), q A B → q A A
Instances For
Quasi-universal: Q(A,A) → Q(A,B) for all B. @cite{van-benthem-1984} §3.1. "no" is quasi-universal: if A∩A = ∅ then A∩B = ∅ for all B.
Equations
- Core.Quantification.QuasiUniversal q = ∀ (A B : α → Prop), q A A → q A B
Instances For
Almost-connected: Q(A,B) → Q(A,C) ∨ Q(C,B) for all C. @cite{van-benthem-1984} §3.1: equivalent to transitivity of ¬Q. "not all" is almost-connected.
Equations
- Core.Quantification.AlmostConnected q = ∀ (A B C : α → Prop), q A B → q A C ∨ q C B
Instances For
Asymmetric: Q(A,B) → ¬Q(B,A). @cite{peters-westerstahl-2006} Ch 6.4. Strictly stronger than antisymmetric: antisymmetry allows Q(A,B) ∧ Q(B,A) when A = B; asymmetry forbids it entirely. Under CONSERV + ISOM, no non-trivial quantifier is asymmetric (P&W Ch 6.4).
Equations
- Core.Quantification.QAsymmetric q = ∀ (A B : α → Prop), q A B → ¬q B A
Instances For
Reflexive (relational vocabulary): Q(A,A) for all A.
Definitionally equal to PositiveStrong; included for relational vocabulary
alignment with @cite{peters-westerstahl-2006} Ch 6.4 and @cite{van-benthem-1984}.
Equations
Instances For
Irreflexive (relational vocabulary): ¬Q(A,A) for all A.
Definitionally equal to NegativeStrong; included for relational vocabulary
alignment with @cite{peters-westerstahl-2006} Ch 6.4.
Instances For
Circular: Q(A,B) ∧ Q(B,C) → Q(C,A). @cite{peters-westerstahl-2006} Ch 6.4. No natural language quantifier is non-trivially circular (under CONSERV + ISOM). Together with transitivity, circularity forces quasi-reflexivity.
Equations
- Core.Quantification.QCircular q = ∀ (A B C : α → Prop), q A B → q B C → q C A
Instances For
VAR (Variety): Q is non-trivial — it both accepts and rejects some pair. @cite{van-benthem-1984} §2: rules out degenerate quantifiers like "at least 2" on singleton domains. Used as hypothesis in most uniqueness theorems.
Equations
- Core.Quantification.Variety q = ((∃ (A : α → Prop) (B : α → Prop), q A B) ∧ ∃ (A : α → Prop) (B : α → Prop), ¬q A B)
Instances For
Double monotonicity type (@cite{van-benthem-1984} §4.2). The logical Square of Opposition maps to four double-monotonicity types: all = ↓MON↑, some = ↑MON↑, no = ↓MON↓, not all = ↑MON↓.
- upUp : DoubleMono
- downUp : DoubleMono
- upDown : DoubleMono
- downDown : DoubleMono
Instances For
Equations
- Core.Quantification.instDecidableEqDoubleMono 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
Restrictor monotonicity determines projection type for embedded trivalent content (@cite{ramotowska-marty-romoli-santorio-2025}).
Restrictor-↓ (every, no) = conjunctive/strong = fragile under gaps. Restrictor-↑ (some, not-every) = disjunctive/weak = robust under gaps.
This is the monotonicity-theoretic explanation of why quantifier STRENGTH (not polarity) determines truth-value judgments for counterfactuals and other trivalent phenomena.
Equations
- Core.Quantification.DoubleMono.downUp.toProjectionType = Core.Duality.ProjectionType.conjunctive
- Core.Quantification.DoubleMono.downDown.toProjectionType = Core.Duality.ProjectionType.conjunctive
- Core.Quantification.DoubleMono.upUp.toProjectionType = Core.Duality.ProjectionType.disjunctive
- Core.Quantification.DoubleMono.upDown.toProjectionType = Core.Duality.ProjectionType.disjunctive
Instances For
Right continuity (CONT): if Q(A,B₁) and Q(A,B₂) hold and B₁ ⊆ B ⊆ B₂, then Q(A,B). @cite{van-benthem-1984} §4.3: all right-monotone quantifiers are continuous. "precisely one" is continuous but non-monotone.
Equations
- Core.Quantification.RightContinuous q = ∀ (A B B₁ B₂ : α → Prop), (∀ (x : α), B₁ x → B x) → (∀ (x : α), B x → B₂ x) → q A B₁ → q A B₂ → q A B
Instances For
Filtrating: Q(A,B) ∧ Q(A,C) → Q(A, B∩C). @cite{van-benthem-1984} Thm 4.4.2: "all" is the only filtrating quantifier (under VAR*). This is because filtrating ↔ filter (closure under ∩), and only the principal filter at A (= inclusion) satisfies CONSERV.
Equations
- Core.Quantification.Filtrating q = ∀ (A B C : α → Prop), q A B → q A C → q A fun (x : α) => B x ∧ C x
Instances For
MU1: All simple (lexicalized) determiners are monotone in scope. @cite{peters-westerstahl-2006} §5.8 Universal 1.
Equations
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MU2: All simple determiners are monotone in at least one restrictor direction. @cite{peters-westerstahl-2006} §5.8 Universal 2.
Equations
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MU3: All simple Mon↑ determiners are smooth. @cite{peters-westerstahl-2006} §5.8 Universal 3.
Equations
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MU4: All simple Mon↓ determiners are co-smooth. @cite{peters-westerstahl-2006} §5.8 Universal 4.
Equations
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QUANT (Isomorphism closure): Q is invariant under permutations of the domain. Model-agnostic version: Q(A,B) depends only on the pointwise pattern, not on which specific elements satisfy A and B.
This is the type ⟨1,1⟩ (binary) generalization of @cite{mostowski-1957}'s permutation invariance. Mostowski's original condition applies to type ⟨1⟩ (unary) quantifiers; the extension to binary determiners is due to @cite{van-benthem-1984} (building on Lindström 1966).
The model-specific version in Semantics.Quantification.Quantifier.Quantity
uses cardinalities directly, which requires FiniteModel. This version
captures the same intuition without model infrastructure.
@cite{van-benthem-1984} §2: CONSERV + QUANT together reduce Q's behavior to pairs (a, b) where a = |A \ B| and b = |A ∩ B|.
Equations
- Core.Quantification.QuantityInvariant q = ∀ (A B A' B' : α → Prop) (f : α → α), Function.Bijective f → (∀ (x : α), A (f x) ↔ A' x) → (∀ (x : α), B (f x) ↔ B' x) → (q A B ↔ q A' B')
Instances For
Outer negation: (~Q)(A,B) = ¬Q(A,B) (B&C §4.11).
Example: ~every = not-every ("Not every student passed").
Equations
- Core.Quantification.outerNeg q R S = ¬q R S
Instances For
Inner negation: (Q~)(A,B) = Q(A, ¬B) (B&C §4.11).
Example: every~ = every...not ("Every student didn't pass").
Equations
- Core.Quantification.innerNeg q R S = q R fun (x : α) => ¬S x
Instances For
Dual: Q̌ = ~(Q~) = ¬Q(A, ¬B) (B&C §4.11).
Example: every̌ = some, somě = every.
Equations
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Meet of two GQ denotations: (f ∧ g)(A,B) = f(A,B) ∧ g(A,B). K&S (20): conjunction of dets, e.g., "both John's and Mary's". Also: "between n and m" = (at least n) ∧ (at most m).
Equations
- Core.Quantification.gqMeet f g R S = (f R S ∧ g R S)
Instances For
Join of two GQ denotations: (f ∨ g)(A,B) = f(A,B) ∨ g(A,B). K&S (24): disjunction of dets, e.g., "either John's or Mary's".
Equations
- Core.Quantification.gqJoin f g R S = (f R S ∨ g R S)
Instances For
Restriction of a GQ by a restricting function (adjective/relative clause). K&S (66): h_f(s) = h(f(s)). In our representation, the adjective narrows the restrictor: "tall student" = student ∧ tall.
Equations
- Core.Quantification.adjRestrict q adj R S = q (fun (x : α) => R x ∧ adj x) S
Instances For
NP denotation (type ⟨1⟩): a property of properties.
This is the model-agnostic version of Ty.ett from TypeShifting.lean.
P&W §2.1: an NP like "every student" denotes a set of sets.
Equations
- Core.Quantification.NPQ α = ((α → Prop) → Prop)
Instances For
Restriction: given a GQ Q and restrictor A, produce the type ⟨1⟩
quantifier Q^[A] (P&W §3.2.2). restrict Q A B = Q A B.
Equations
- Core.Quantification.restrict q A = q A
Instances For
A type ⟨1⟩ quantifier Q "lives on" A iff Q(B) ↔ Q(A ∩ B) for all B. P&W §3.2.2: the restricted quantifier depends only on elements of A.
Equations
- Core.Quantification.LivesOn Q A = ∀ (B : α → Prop), Q B ↔ Q fun (x : α) => A x ∧ B x
Instances For
Montagovian individual: the type ⟨1⟩ quantifier I_a = {X : a ∈ X}. P&W §3.2.3: an entity lifts to the principal ultrafilter it generates.
Equations
- Core.Quantification.individual a P = P a
Instances For
ScopeUpwardMono q is ∀ R, Monotone (q R) under the Pi-of-Prop
ordering (where S ≤ S' is ∀ x, S x → S' x and Prop-valued
≤ is implication). This bridges GQ-level monotonicity to Mathlib's
Monotone, which is what Polarity.lean uses
(IsUpwardEntailing = Monotone).
ScopeDownwardMono q is ∀ R, Antitone (q R) under the Pi-of-Prop
ordering.