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Studies.Bhadra2024

Bhadra (2024): Verb roots encode outcomes #

This file formalizes Bhadra's account of the reversative prefix un- and the restitutive prefix re-. Every dynamic transitive root lexically carries a set of outcomes, the states its object can be in at the right boundary of the event, while a contextual set of thresholds collects the states an object can be in at the left boundary. Potential-for-change roots such as fold, wrap and coil have several outcomes, change-of-state and impingement-effecting roots such as break, shatter and hit have a single lexically specified outcome, and roots unspecified for change have none. Un- presupposes a prior base event whose result the object is still in and several outcomes, and asserts that the object returns to the base event's initial state. Re- presupposes a prior base event with the same result and requires that the base action not leave the object where that result cannot be restored. Cardinality thus governs un- alone and threshold structure governs re-, so the two prefixes overlap exactly on the potential-for-change class.

The hierarchy of outcome sets cross-classifies Beavers's affectedness hierarchy. Beavers places the impingement-effecting verbs with the potential-for-change verbs, while their single outcome puts them with the change-of-state verbs, whose single outcome may be a quantized or a non-quantized change.

Implementation notes #

References #

Outcome cardinality #

An outcome cardinality is the tier of an outcome set, ordered empty < singleton < multi (62).

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      noncomputable def Bhadra2024.OutcomeCardinality.ofSet {State : Type u_1} (O : Set State) :

      The tier of an outcome set is multi when it is nontrivial, empty when it is empty, and singleton otherwise.

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        theorem Bhadra2024.OutcomeCardinality.ofSet_eq_multi {State : Type u_1} {O : Set State} (h : O.Nontrivial) :
        theorem Bhadra2024.OutcomeCardinality.ofSet_eq_singleton {State : Type u_1} {O : Set State} (hne : O.Nonempty) (hnt : ¬O.Nontrivial) :
        theorem Bhadra2024.OutcomeCardinality.ofSet_eq_empty {State : Type u_1} {O : Set State} (h : ¬O.Nonempty) :
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        theorem Bhadra2024.OutcomeCardinality.ofSet_singleton {State : Type u_1} (s : State) :

        An outcome class classifies dynamic transitive roots by what their outcome sets encode, the potential-for-change class (60) and the classes with a lexically specified result or none (61a–h).

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            The outcome tier of a class is multi-membered for potential-for-change roots, singleton for every root with a lexically specified result, and empty for roots unspecified for change (62).

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              Potential-for-change roots are the only class whose outcome sets are multi-membered.

              States, boundaries, and roots #

              @[reducible, inline]
              abbrev Bhadra2024.StateFunction (Entity : Type u_1) (State : Type u_2) (T : Type u_3) :
              Type (max (max u_1 u_2) u_3)

              A state function gives an object's state at each time, a lifespan point (53).

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                def Bhadra2024.resState {Entity : Type u_1} {State : Type u_2} {T : Type u_3} {E : Type u_4} [LinearOrder T] [Event.TemporalTrace E T] (k : StateFunction Entity State T) (e : E) (x : Entity) :
                State

                res(e)(x) is the object's state at the right boundary of e (64).

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                  def Bhadra2024.preState {Entity : Type u_1} {State : Type u_2} {T : Type u_3} {E : Type u_4} [LinearOrder T] [Event.TemporalTrace E T] (k : StateFunction Entity State T) (e : E) (x : Entity) :
                  State

                  pre(e)(x) is the object's state at the left boundary of e (65).

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                    structure Bhadra2024.VerbOutcomes (E : Type u_5) (Entity : Type u_6) (State : Type u_7) :
                    Type (max (max u_5 u_6) u_7)

                    A verb root, as the prefixes see it, is its base predicate together with the lexical outcome set of states at the right boundary and the contextual threshold set of states at the left boundary ((56), (60)).

                    • verb : E → Entity → Prop

                      The base predicate P(e)(x).

                    • outcomes : Set State

                      The outcome set O.

                    • thresholds : Set State

                      The threshold set T.

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                      noncomputable def Bhadra2024.VerbOutcomes.cardinality {Entity : Type u_1} {State : Type u_2} {E : Type u_4} (vro : VerbOutcomes E Entity State) :

                      The cardinality of a root is the tier of its outcome set.

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                        The prefixes as result-state modifiers #

                        def Bhadra2024.unSem {Entity : Type u_1} {State : Type u_2} {T : Type u_3} {E : Type u_4} [LinearOrder T] [Event.TemporalTrace E T] (k : StateFunction Entity State T) (vro : VerbOutcomes E Entity State) (e : E) (x : Entity) :

                        Reversative un- (66) requires a prior base event e' whose result is the state the un- event starts from and a multi-membered outcome set, and returns the object to the base event's initial state. The vacuous ∃ Q. Q(e)(x) of the assertion is dropped.

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                          def Bhadra2024.reSem {Entity : Type u_1} {State : Type u_2} {T : Type u_3} {E : Type u_4} [LinearOrder T] [Event.TemporalTrace E T] (k : StateFunction Entity State T) (vro : VerbOutcomes E Entity State) (e : E) (x : Entity) :

                          Restitutive re- ((68), (72)) requires a prior base event e' with the same result, whose result state is an admissible start state, so that the base action does not leave the object where its result cannot be restored, and requires the base predicate to hold of the re- event. It places no demand on the cardinality of the outcome set.

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                            theorem Bhadra2024.subsingleton_blocks_un {Entity : Type u_1} {State : Type u_2} {T : Type u_3} {E : Type u_4} [LinearOrder T] [Event.TemporalTrace E T] (k : StateFunction Entity State T) (vro : VerbOutcomes E Entity State) (h : ¬vro.outcomes.Nontrivial) (e : E) (x : Entity) :
                            ¬unSem k vro e x

                            A root whose outcome set is not multi-membered cannot host un- (67).

                            theorem Bhadra2024.singleton_blocks_un {Entity : Type u_1} {State : Type u_2} {T : Type u_3} {E : Type u_4} [LinearOrder T] [Event.TemporalTrace E T] (k : StateFunction Entity State T) (vro : VerbOutcomes E Entity State) (s : State) (hs : vro.outcomes = {s}) (e : E) (x : Entity) :
                            ¬unSem k vro e x
                            theorem Bhadra2024.empty_blocks_un {Entity : Type u_1} {State : Type u_2} {T : Type u_3} {E : Type u_4} [LinearOrder T] [Event.TemporalTrace E T] (k : StateFunction Entity State T) (vro : VerbOutcomes E Entity State) (hs : vro.outcomes = ∅) (e : E) (x : Entity) :
                            ¬unSem k vro e x
                            theorem Bhadra2024.un_requires_multi {Entity : Type u_1} {State : Type u_2} {T : Type u_3} {E : Type u_4} [LinearOrder T] [Event.TemporalTrace E T] (k : StateFunction Entity State T) (vro : VerbOutcomes E Entity State) (e : E) (x : Entity) (h : unSem k vro e x) :

                            Hosting un- forces a root's outcome set into the multi-membered tier.

                            theorem Bhadra2024.not_reSem_of_outcome_not_threshold {Entity : Type u_1} {State : Type u_2} {T : Type u_3} {E : Type u_4} [LinearOrder T] [Event.TemporalTrace E T] (k : StateFunction Entity State T) (vro : VerbOutcomes E Entity State) (x : Entity) (h : ∀ (e' : E), vro.verb e' x → resState k e' x ∉ vro.thresholds) (e : E) :
                            ¬reSem k vro e x

                            A base action whose result is never an admissible start state blocks re- (72).

                            Worked roots #

                            def Bhadra2024.ev₁ :
                            NonemptyInterval ℤ

                            ev₁ is the base event of the scenario, over [0, 5].

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                              def Bhadra2024.ev₂ :
                              NonemptyInterval ℤ

                              ev₂ is the prefixed event of the scenario, over [10, 15].

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                                def Bhadra2024.acts :
                                NonemptyInterval ℤ → Unit → Prop

                                The base predicate of every worked root holds of the scenario's two events.

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                                  def Bhadra2024.twice {State : Type u_5} (start result : State) :
                                  StateFunction Unit State ℤ

                                  A root whose action carries the object from start to result at the base event and again at the prefixed event, both acting on the same object.

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                                    def Bhadra2024.andBack {State : Type u_5} (start result : State) :
                                    StateFunction Unit State ℤ

                                    A root whose action carries the object from start to result at the base event and back to start at the prefixed event.

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                                    • Bhadra2024.andBack start result t x✝ = if t ≤ 0 then start else if t ≤ 10 then result else start
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                                      A parchment under folding is flat, slightly creased, folded or tightly folded (54).

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                                          def Bhadra2024.foldVRO :
                                          VerbOutcomes (NonemptyInterval ℤ) Unit ParchmentState

                                          Fold is a potential-for-change root (60), with a multi-membered outcome set, and a folded parchment can be folded again.

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                                            Veena unfolded the parchment is true in the scenario, the worked derivation of (66).

                                            Re- attaches to fold as well, on the multi-membered tier.

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                                              def Bhadra2024.instReprLimbState.repr :
                                              LimbState → ℕ → Std.Format
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                                                def Bhadra2024.breakLimbVRO :
                                                VerbOutcomes (NonemptyInterval ℤ) Unit LimbState

                                                Break applied to a limb (61a) has a single result, and a broken limb admits another breaking (73a).

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                                                  def Bhadra2024.breakSewerVRO :
                                                  VerbOutcomes (NonemptyInterval ℤ) Unit LimbState

                                                  Break applied to a sewer has the same single result, which a sewer cannot informatively reach again (73a).

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                                                    theorem Bhadra2024.breakLimb_not_un (k : StateFunction Unit LimbState ℤ) (e : NonemptyInterval ℤ) :

                                                    #Unbreak a limb fails, the outcome set being a singleton (67).

                                                    Rebreak a limb is true in the scenario (73a).

                                                    #Rebreak a sewer fails, since a broken sewer is not an admissible start state (73a).

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                                                        def Bhadra2024.hitVRO :
                                                        VerbOutcomes (NonemptyInterval ℤ) Unit SurfaceState

                                                        Hit is an impingement-effecting root (61g), with a single, irreversible surface alteration.

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                                                          theorem Bhadra2024.hit_not_un (k : StateFunction Unit SurfaceState ℤ) (e : NonemptyInterval ℤ) :
                                                          ¬unSem k hitVRO e ()

                                                          *Unhit fails (25).

                                                          *Rehit fails, since impingement leaves the surface altered and never again unaltered (48).

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                                                              def Bhadra2024.loadVRO :
                                                              VerbOutcomes (NonemptyInterval ℤ) Unit TruckState

                                                              Load is a degree achievement (70), with a single contextually salient result that does not prevent loading again.

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                                                                Raj reloaded the truck is true in the scenario (69a).

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                                                                    def Bhadra2024.shatterVRO :
                                                                    VerbOutcomes (NonemptyInterval ℤ) Unit MirrorState

                                                                    Shatter (71) has a single result that leaves the object outside every threshold.

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                                                                      #The children reshattered the mirror fails (69b).

                                                                      Re- is indifferent to outcome cardinality, attaching to a root with a single outcome.

                                                                      The affectedness hierarchy (§2.4, (20), (62)) #

                                                                      BeaversDegree c d holds when the paper places verbs of the class c at the degree d of Beavers's affectedness hierarchy ((20), §2.4.2).

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                                                                        Potential-for-change and impingement-effecting verbs share a degree of affectedness but not an outcome tier, which is why the paper separates them (§2.4.2, (62)).

                                                                        Consumption verbs and degree achievements share the singleton tier but not a degree of affectedness, the tier of lexically specified change including quantized and non-quantized change ((62)).