Templatic Heads and Event Structure Composition

@cite{beavers-koontz-garboden-2020} @cite{rappaport-hovav-levin-1998}

The B&K-G architecture decomposes event structure into templatic heads that combine with roots. The three primitive heads are:

• v_act — activity (Davidsonian event predicate)
• v_become — change of state ([BECOME [x ⟨STATE⟩]])
• v_cause — causation ([e₁ CAUSE e₂])

A root attaches to a head in one of two structural positions:

• adjoined — modifier of a head (typical of manner roots)
• complement — argument of a head (typical of state roots)

The familiar @cite{rappaport-hovav-levin-1998} templates (state, activity, achievement, accomplishment) are compositions of these primitives — see EventStructure.toTemplate.

inductive Semantics.Lexical.Roots.TemplaticHead : Type

The three primitive event-structural heads (@cite{beavers-koontz-garboden-2020} ch. 1, ch. 5).

• v_act : TemplaticHead
• v_become : TemplaticHead
• v_cause : TemplaticHead

@[implicit_reducible]

instance Semantics.Lexical.Roots.instDecidableEqTemplaticHead : DecidableEq TemplaticHead

Equations

• Semantics.Lexical.Roots.instDecidableEqTemplaticHead x✝ y✝ = if h : x✝.ctorIdx = y✝.ctorIdx then isTrue ⋯ else isFalse ⋯

def Semantics.Lexical.Roots.instReprTemplaticHead.repr : TemplaticHead → Nat → Std.Format

Equations

• One or more equations did not get rendered due to their size.

@[implicit_reducible]

instance Semantics.Lexical.Roots.instReprTemplaticHead : Repr TemplaticHead

Equations

• Semantics.Lexical.Roots.instReprTemplaticHead = { reprPrec := Semantics.Lexical.Roots.instReprTemplaticHead.repr }

structure Semantics.Lexical.Roots.EventStructure : Type

An event structure: a list of templatic heads (outermost first) composed with a root in a specific structural position.

Examples:

• ⟨[v_act], jog, adjoined⟩ — pure activity (jog)
• ⟨[v_become], blossom, complement⟩ — achievement
• ⟨[v_cause, v_become], crack, complement⟩ — accomplishment
• ⟨[v_cause, v_become], hand, adjoined⟩ — caused result with manner root in adjoined position

• heads : List TemplaticHead
• root : Root
• position : RootPosition

def Semantics.Lexical.Roots.instReprEventStructure.repr : EventStructure → Nat → Std.Format

Equations

• One or more equations did not get rendered due to their size.

@[implicit_reducible]

instance Semantics.Lexical.Roots.instReprEventStructure : Repr EventStructure

Equations

• Semantics.Lexical.Roots.instReprEventStructure = { reprPrec := Semantics.Lexical.Roots.instReprEventStructure.repr }

def Semantics.Lexical.Roots.EventStructure.hasHead (es : EventStructure) (h : TemplaticHead) : Bool

Does the event structure include a particular head?

Equations

• es.hasHead h = es.heads.contains h

def Semantics.Lexical.Roots.EventStructure.hasAct (es : EventStructure) : Bool

Has activity head.

Equations

• es.hasAct = es.hasHead Semantics.Lexical.Roots.TemplaticHead.v_act

def Semantics.Lexical.Roots.EventStructure.hasBecome (es : EventStructure) : Bool

Has BECOME head.

Equations

• es.hasBecome = es.hasHead Semantics.Lexical.Roots.TemplaticHead.v_become

def Semantics.Lexical.Roots.EventStructure.hasCause (es : EventStructure) : Bool

Has CAUSE head.

Equations

• es.hasCause = es.hasHead Semantics.Lexical.Roots.TemplaticHead.v_cause

def Semantics.Lexical.Roots.activityOf (r : Root) : EventStructure

A pure activity: [v_act] with manner root adjoined. [x ACT⟨manner⟩]

Equations

• Semantics.Lexical.Roots.activityOf r = { heads := [Semantics.Lexical.Roots.TemplaticHead.v_act], root := r, position := Semantics.Lexical.Roots.RootPosition.adjoined }

def Semantics.Lexical.Roots.achievementOf (r : Root) : EventStructure

An achievement: [v_become] with state root as complement. [BECOME [x ⟨STATE⟩]]

Equations

• Semantics.Lexical.Roots.achievementOf r = { heads := [Semantics.Lexical.Roots.TemplaticHead.v_become], root := r, position := Semantics.Lexical.Roots.RootPosition.complement }

def Semantics.Lexical.Roots.accomplishmentOf (r : Root) : EventStructure

An accomplishment: [v_cause, v_become] with state root as complement to BECOME. [[x ACT] CAUSE [BECOME [y ⟨STATE⟩]]]

Equations

• One or more equations did not get rendered due to their size.