Lexical-Functional Grammar
Ash Asudeh Carleton University University of Iceland July 3, 2009
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Lexical-Functional Grammar Ash Asudeh Carleton University - - PowerPoint PPT Presentation
Lexical-Functional Grammar Ash Asudeh Carleton University University of Iceland July 3, 2009 1 Architecture and Structures 2 Basic Syntactic Architecture of LFG Two basic, simultaneous representations of syntax:
Ash Asudeh Carleton University University of Iceland July 3, 2009
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phrase structure Annotated trees
(subject, object, etc.), tense, case, agreement, predication, local and non-local dependencies Feature structures/attribute-value matrices
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anaphoric structure
Meaning
c-structure f-structure semantic structure
π φ σ α δ
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i-structure
Meaning
c-structure m-structure a-structure f-structure s-structure model
π µ φ ι ισ ρ ρσ λ σ α ψ
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External structures (modelled by LFG c-structures) vary across languages.
Internal structures (modelled by LFG f-structures) are largely invariant across languages.
The mapping from c-structure to f-structure is not one-to-one, but it is monotonic (information-preserving).
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That of ‘the two small children are chasing that dog’
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(1)
underlying concept of ‘the two small children are chasing that dog’
(Note: this is a slight simplification)
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That of ‘the two small children are chasing that dog’
S NP wita-jarra-rlu small-DUAL-ERG Aux ka-pala pres-3duSUBJ V wajili-pi-nyi chase-NPAST NP yalumpu that-ABS NP kurdu-jarra-rlu child-DUAL-ERG NP maliki dog-ABS
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common syntactic constraints on the two languages.
(1)
(2) a. Napaljarri-rli ka-nyanu paka-rni Napaljarri-ERG PRES-REFL hit-NONPAST ‘Napaljarri is hitting herself.’ b. * Napaljarri ka-nyanu paka-rni Napaljarri.ABS PRES-REFL hit-NONPAST ‘Herself is hitting Napaljarri.’
➡ How should abstract grammatical relations be captured?
Transformational Grammar: configurationally, using a uniform syntactic representation LFG: non-configurationally, using a separate syntactic representation
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descriptions of those objects (i.e. constraints on the objects).
expressions: ➡disjunction, optionality, arbitrary repetition (Kleene plus [+] and star [*])
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etc.), and grammatical dependencies (raising, control, unbounded dependencies) (1)David devoured a sandwich.
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Feature Value: complex (semantic form) Value: complex (feature structure) Feature Feature Value: complex (feature structure) Feature Feature Value: simple (semantic form) Feature Value: simple (semantic form) Value: simple
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All the grammatical functions subcategorized by a predicate must be present in the f-structure.
(1)* David devoured.
Devour <SUBJ, OBJ>
Only the grammatical functions subcategorized by a predicate may be present in the f-structure.
(2)* David devoured a sandwich that it was raining.
No attribute may have more than one value.
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➡Multiple instances of semantic forms cannot unify, even if the semantic forms are otherwise compatible. (1) * David devoured a sandwich a sandwich.
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PRED)=‘yawn SUBJ ’
VFORM)=FINITE
TENSE)=PRES
SUBJ PERS)=3
SUBJ NUM)=SG
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relevant relation, but it is certainly the most common way of specifying constraints on f-structures in LFG. So the term has stuck.
1.Defining Equations
These equations define the f-structure by specifying which features have which values. They ‘make it so’. Defining equations are stated with a simple equality (or other relation symbol).
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2.Constraining Equations
These equations further constrain the f-structure once it has been constructed. In other words:
minimal model.
There are a number of different kinds of constraining equations, but the
equality like this:
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The PRED of ‘sneeze’ is ‘SNEEZE<SUBJ>’. Also (conjunction): Either (disjunction) the VFORM is BASE (i.e. it’s a non-finite form) or it has present tense and it is not the case that (negation) its subject has third person singular agreement features (cf. She sneeze.)
SUBJ PRED) = ‘PRO’)
(26) sneeze
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specifications about paths leading in from f:
specifications about paths leading out from f:
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specifications about paths leading in from f:
specifications about paths leading out from f:
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defining abbreviatory symbols disjunctively:
(*) or Kleene plus (+), where X* means ‘0 or more X’ and X+ means ‘1 or more X’:
as is also the case for the right-hand side of c-structure rules.
GF = { SUBJ | OBJ | OBJθ | OBL | COMP | XCOMP | ADJ | XADJ }
(↑ FOCUS) = (↑ {XCOMP | COMP}∗ GF) (↑ INDEX) = ((GF+ ↑) SUBJ INDEX)
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larger f-structure that contains the same information.*
* This relationship is called subsumption:
In general, a structure A subsumes a structure B if and only if A and B are identical or B contains A and additional information not included in A.
description: the f-description is also true of the infinitely many other f-structures that the intended, minimal f-structure subsumes.
PRED
‘GO SUBJ ’
SUBJ NUM SG PRED
‘GO SUBJ ’
TENSE FUTURE SUBJ PRED
‘PRO’
CASE NOM NUM SG
f subsumes g
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no features that are not mentioned in the f-description may be included.
(1)David sneezed.
(20) (f PRED) ¼ ‘SNEEZEhSUBJi’ (f TENSE) ¼ PAST (f SUBJ) ¼ g (g PRED) ¼ ‘DAVID’
C
s i s t e n t b u t n
i n i m a l f
t r u c t u r e subsumes Minimal consistent f-structure
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PRED)=‘yawn SUBJ ’
VFORM)=FINITE
TENSE)=PRES
SUBJ PERS)=3
SUBJ NUM)=SG
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(3) PRESENT = (
VFORM)=FINITE
(
TENSE)=PRES
3SG = (
SUBJ PERS)=3
(
SUBJ NUM)=SG
(2) yawns (
PRED)=‘yawn SUBJ ’
(
VFORM)=FINITE
(
TENSE)=PRES
(
SUBJ PERS)=3
(
SUBJ NUM)=SG
(4) yawns (
PRED)=‘yawn SUBJ ’
@PRESENT @3SG
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(5) FINITE = (
VFORM)=FINITE PRES-TENSE
= (
TENSE)=PRES PRESENT
= @FINITE @PRES-TENSE
PRES-TENSE FINITE PRESENT
(7) 3PERSONSUBJ = (
SUBJ PERS)=3
SINGSUBJ = (
SUBJ NUM)=SG
3SG = @3PERSONSUBJ @SINGSUBJ
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(9) PRES3SG = @PRESENT @3SG
1) yawns (
PRED)=‘yawn SUBJ ’
@PRES3SG
(4) yawns (
PRED)=‘yawn SUBJ ’
@PRESENT @3SG
PRES-TENSE FINITE
PRESENT
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(15) PRESNOT3SG = @PRESENT @3SG
Negation
(16) (
VFORM)=FINITE
(
TENSE)=PRES
(
SUBJ PERS)=3
(
SUBJ NUM)=SG
PRES-TENSE FINITE
3PERSONSUBJ SINGSUBJ
PRESENT
3SG PRESNOT3SG PRES3SG
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inheritance is interpreted.
as conjunction, no real status for motherhood.
determined contextually at invocation or is built into the template.
(1)
HEAD NOUN C-NOUN GERUND RELATIONAL VERB
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HEAD NOUN C-NOUN GERUND RELATIONAL VERB
PRES-TENSE FINITE
3PERSONSUBJ SINGSUBJ
PRESENT
3SG PRESNOT3SG PRES3SG
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(12) INTRANSITIVE(P) = (
PRED)=‘P SUBJ ’
1) yawns (
PRED)=‘yawn SUBJ ’
@PRES3SG
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PRED)=‘P SUBJ, OBJ ’
(19) TRANS-OR-INTRANS(P) = @TRANSITIVE(P) @INTRANSITIVE(P)
PRED)=‘eat SUBJ, OBJ ’
PRED)=‘eat SUBJ ’
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3PERSONSUBJ SINGSUBJ
PRESENT
3SG
INTRANSITIVE TRANSITIVE
PRES3SG
TRANS-OR-INTRANS
falls bakes cooked
eats yawns
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CASE)
CASE)=NOM
D D=V
CASE) NOM)
The f-structure must have case and if nothing else provides its case, then its case is nominative. Paramerized template for defaults. Also illustrates that parameterized templates can have multiple arguments
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VP V ADVP* = (
ADJUNCT)
(
ADJUNCT-TYPE)=VP-ADJ
= (
ADJUNCT)
@ADJUNCT-TYPE(P)
= (
ADJUNCT-TYPE)=P
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Minimalist Program are well-motivated morphosyntactically, although
structural representation (cf. Blevins 2008).
makes things displace, as evidenced by its displacement.”
makes things displace, as evidenced by its lack of displacement.”
move to subject position, as evidenced by its occupying subject position.”
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elsewhere in the system (Culicover & Jackendoff 2005: ‘honest accounting’).
any kind of natural class within the theory (as opposed to meta- theoretically).
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[Notation from Adger 2003]
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Trigger Move/Internal Merge/Remerge
Do not trigger Move
[Notation from Adger 2003]
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“When [uInfl: ] on Aux is valued by T, the value is strong; when [uInfl: ] on v is valued by T, the value is weak.”
TP
Subject
T
T[past]
NegP
Neg
vP
Subject
v
Verb + v[uInfl]...
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Locality of Matching Agree holds between a feature F on X and a matching feature F
Intervention In a structure [X ... Z ... Y], Z intervenes between X and Y iff X c- commands Z and Z c-commands Y.
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Feature-value unrestrictiveness Feature valuation is unrestricted with respect to what values a valued feature may receive. Free valuation Feature valuation appears freely, subject to locality conditions.
Minimal, but from a theory perspective it is bad: unconstrained theories are less predictive.
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TP
T[singular]
vP
Gilgamesh
v v
miss v[uInfl:singular]
VP
miss
NP
Enkidu
TP
T[past]
vP
Gilgamesh
v v
miss v[uInfl:past]
VP
miss
NP
Enkidu
(1) Gilgamesh missed Enkidu (2) Gilgamesh misses Enkidu
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are also typed
must be a subtype of the other).
restricted, but there is no free valuation
explicit equation in the system.
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types
constraining equations allowed
constraints allowed
number as a natural class.
theoretical statement in an explicit, non-ad-hoc feature theory.
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IP (↑ SUBJ) =↓ NP
Gonzo
↑ = ↓ I′ ↑ = ↓ VP ↑ = ↓ V0
seemed/tried
↑ = ↓ VP ↑ = ↓ V0
to
↑ = ↓ VP ↑ = ↓ V0
leave
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(1)Thora seems like she enjoys hot chocolate. (2)Thora seems like Isak pinched her again. (3)Thora seems like Isak ruined her book. (4)* Thora seems like Isak enjoys hot chocolate. (5)* Thora seems like Isak pinched Justin again. (6)* Thora seems like Isak ruined Justin’s book.
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(7)It seems like there is a problem here. (8)It seems like Thora is upset. (9)It seems like it rained last night. (10) There seems like there’s a problem here. (11) * There seems like it rained last night.
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IP (↑ SUBJ) = ↓ DP
Richard
↑ = ↓ I ↑ = ↓ VP ↑ = ↓ V0
seems / smells
(↑ XCOMP) = ↓ PP ↑ = ↓ P ↑ = ↓ P0
like
(↑ COMP) = ↓ IP (↑ SUBJ) = ↓ DP
he
↑ = ↓ I ↑ = ↓ VP
smokes
seems
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PRED
‘seem/smell’
SUBJ XCOMP
PRED
‘like’
SUBJ
‘Richard’
PRED
‘smoke’
SUBJ
PRED
‘pro’
PERS
3
NUM
sg
GEND
masc
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IP (↑ SUBJ) = ↓ DP
There
↑ = ↓ I ↑ = ↓ VP ↑ = ↓ V0
seemed
(↑ XCOMP) = ↓ PP ↑ = ↓ P0
like
(↑ XCOMP) = ↓ IP (↑ SUBJ) = ↓ DP
there
↑ = ↓ I
was a problem
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PRED
‘seem’
SUBJ XCOMP
PRED
‘like’
SUBJ XCOMP
PRED
‘be’
SUBJ
there
PRED
‘problem’
SPEC
‘a’
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unbounded dependency is represented with a functional uncertainty:
(1) [What] [did Kim claim that Sandy suspected that Robin knew] [ ]
top middle bottom
top middle bottom (2) [What] [did Kim claim that Sandy suspected that Robin gave Bo] [ ]
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CP NP N
C C
IP NP N
I VP V
FOCUS PRED
‘PRO’
PRONTYPE WH Q PRED
‘LIKE SUBJ,OBJ ’
SUBJ PRED
‘DAVID’
OBJ
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FOCUS) =
FOCUS) = (
Q) = ( FOCUS WHPATH)
Q PRONTYPE) WH
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(1)NP: Who do you like? (2)PP: To whom did you give a book? (3)AdvP: When did you yawn? (4)AP: How tall is Chris?
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English QFOCUSPATH:
XCOMP COMP
(
LDD) OBJ
(
TENSE) ADJ
(
TENSE) GF GF
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(1)[Whose book] did you read? (2)[Whose brother’s book] did you read? (3)[In which room] do you teach?
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26) a man who Chris saw
PRED
‘MAN’
SPEC PRED
‘A’
ADJ TOPIC PRED
‘PRO’
PRONTYPE REL RELPRO PRED
‘SEE SUBJ,OBJ ’
SUBJ PRED
‘CHRIS’
OBJ
NP Det
a
N N N
man
CP NP N
who
C IP NP N
Chris
I VP V
saw
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CP RelP (
TOPIC) =
(
TOPIC) = (
RTOPICPATH) (
RELPRO) = ( TOPIC RELPATH)
(
RELPRO PRONTYPE) REL
C =
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(1)NP: a man who I selected (2)PP: a man to whom I gave a book (3)AP: the kind of person proud of whom I could never be (4)AdvP: the city where I live
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English RTOPICPATH:
XCOMP COMP
(
LDD) OBJ
(
TENSE) ADJ
(
TENSE) GF GF
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(1)the man [who] I met (2)the man [whose book] I read (3)the man [whose brother’s book] I
read
(4)the report [the cover of which] I
designed
(5)the man [faster than whom] I can
run
(6)the kind of person [proud of
whom] I could never be
(7)the report [the height of the
lettering on the cover of which] the government prescribes
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(27) a man whose book Chris read
PRED
‘MAN’
SPEC PRED
‘A’
ADJ TOPIC SPEC PRED
‘PRO’
PRONTYPE REL PRED
‘BOOK’
RELPRO PRED
‘READ SUBJ,OBJ ’
SUBJ PRED
‘CHRIS’
OBJ
NP Det
a
N N N
man
CP NP Det
whose
N N
book
C IP NP N
Chris
I VP V
read
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(1)Who do you think [__ left]? (2)* Who do you think [that __ left]? (3)* What do you wonder [if __ smells bad]? (4)Who do you think [__ should be trusted]? (5)* Who do you think [that __ should be trusted]? (6)Who do you think [that, under no circumstances, __ should be trusted]? (7)Who do you wonder [if, under certain circumstances, __ could be trusted]?
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precedence of c-structure to talk about precedence between bits
inverse of the c-structure–f-structure mapping function ϕ.
that map to its argument f-structure node. F-precedence An f-structure f f-precedes an f-structure g (f <f g) if and only if for all n1 ∈ ϕ-1( f ) and for all n2 ∈ ϕ-1( g ), n1 c-precedes n2.
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that That-Trace is a ‘surfacy’ phenomenon (cf. ECP as a PF constraint in recent Minimalism).
string c-structure f-structure π φ
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element’), which we define as Rightstring(π-1(*)), where * designates the current c-structure node in a phrase structure rule element or lexical entry.
adjacent to me’.
because π is bijective, since c-structures are trees.
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That-Trace.
right-adjacent string element to the complementizer must be locally realized.
function in the f-structure corresponding to the element that
not f-precede the complementizer’s f-structure.
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(1)Whose car did you drive __? (2)* Whose did you drive [__ car]?
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English QFOCUSPATH:
XCOMP COMP
(
LDD) OBJ
(
TENSE) ADJ
(
TENSE) GF GF − SPEC}
the extraction from passing through a SPEC in the first part.
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English QFOCUSPATH:
XCOMP COMP
(
LDD) OBJ
(
TENSE) ADJ
(
TENSE) GF GF − SPEC}
English QFOCUSPATH:
XCOMP COMP
(
LDD) OBJ
(
TENSE) ADJ
(
TENSE) GF GF − SPEC}
¬(← UDF)
the attribute that the constraint is attached to.
value of the attribute that the constraint is attached to.
unbounded dependency function UDF , where UDF = {TOPIC | FOCUS}.
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successive marking along the extraction path, have motivated the claim that extraction/movement is ‘cyclic’ (not all at once). Cf. Phases in Minimalism.
have wrongly assumed, but rather that unbounded dependencies should
constructed.
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) a. Shíl thought mé I goN
PRT
mbeadh would-be sé he ann there I thought that he would be there.
said mé I gurL goN+PAST shíl thought mé I goN
PRT
mbeadh would-be sé he ann there I said that I thought that he would be there.
[the man]j aL
PRT
shíl thought mé I aL
PRT
bheadh would-be
j
ann there the man that I thought would be there
[the man]j aL
PRT
dúirt said mé I aL
PRT
shíl thought mé I aL
PRT
bheadh would-be
j
ann there The man that I said I thought would be there
[the man]j aL
PRT
shíl thought
j
goN
PRT
mbeadh would-be sé he ann there the man that thought he would be there
via Bouma et al. (2001).
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syntactic formalism that supports a notion of headedness.
categorial syntax.
logic of composition is commutative, unlike in Categorial Grammar.
Dalrymple (1999, 2001), Crouch & van Genabith (2000), Asudeh (2004, 2005a,b, in prep.), Lev 2007, Kokkonidis (in press)
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(proof terms)
Meaning language term Composition language term
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Application : Implication Elimination · · · a : A · · · f : A B
E
f (a) : B Abstraction : Implication Introduction [x : A]1 · · · f : B
I,1
λx.f : A B
Pairwise Conjunction Substitution : Elimination · · · a : A ⊗ B [x : A]1 [y : B]2 · · · f : C
⊗E,1,2
let a be x × y in f : C
Beta reduction for let: let a × b be x × y in f ⇒β f [a/x, b/y]
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1′. mary : gσe 2′. laugh : gσe ⊸ fσt
1′′. mary : m 2′′. laugh : m ⊸ l
Proof
E ⊸, 1, 2
Proof mary : m laugh : m ⊸ l
⊸E
laugh(mary) : l
PRED
SUBJ
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λRλS.most(R, S) : (v ⊸ r) ⊸ ∀X .[(p ⊸ X ) ⊸ X ] president∗ : v ⊸ r λS.most(president∗, S) : ∀X .[(p ⊸ X ) ⊸ X ] speak : p ⊸ s
⊸E, [s/X]
most(president∗, speak) : s
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PRED
‘speakSUBJ, OBJ’
SUBJ
PRED
‘president’
SPEC
‘most’
OBJ
PRED
‘language’
SPEC
‘at-least-one’
(v1 ⊸ r1) ⊸ ∀X .[(p ⊸ X ) ⊸ X ]
(v2 ⊸ r2) ⊸ ∀Y .[(l ⊸ Y ) ⊸ Y ]
Single parse ➡ Multiple scope possibilities (Underspecification through quantification)
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λRλS.most(R, S) : (v1 ⊸ r1) ⊸ ∀X .[(p ⊸ X ) ⊸ X ] president∗ : v1 ⊸ r1 λS.most(president∗, S) : ∀X .[(p ⊸ X ) ⊸ X ] λPλQ.a-l-o(P, Q) : (v2 ⊸ r2) ⊸ ∀Y .[(l ⊸ Y ) ⊸ Y ] lang : v2 ⊸ r2 λQ.a-l-o(lang, Q) : ∀Y .[(l ⊸ Y ) ⊸ Y ] λxλy.speak(x, y) : p ⊸ l ⊸ s [z : p]1 λy.speak(z, y) : l ⊸ s [s/Y ] a-l-o(lang, λy.speak(z, y)) : s
⊸I,1
λz.a-l-o(lang, λy.speak(z, y)) : p ⊸ s [s/X] most(president∗, λz.a-l-o(lang, λy.speak(z, y))) : s
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λPλQ.a-l-o(P, Q) : (v2 ⊸ r2) ⊸ ∀Y .[(l ⊸ Y ) ⊸ Y ] lang : v2 ⊸ r2 λQ.a-l-o(lang, Q) : ∀Y .[(l ⊸ Y ) ⊸ Y ] λRλS.most(R, S) : (v1 ⊸ r1) ⊸ ∀X .[(p ⊸ X ) ⊸ X ] president∗ : v1 ⊸ r1 λS.most(president∗, S) : ∀X .[(p ⊸ X ) ⊸ X ] λyλx.speak(x, y) : l ⊸ p ⊸ s [z : l]1 λx.speak(x, z) : p ⊸ s [s/X] most(president∗, λx.speak(x, z)) : s
⊸I,1
λz.most(president∗, λx.speak(x, z)) : l ⊸ s [s/Y ] a-l-o(lang, λz.most(president∗, λx.speak(x, z))) : s
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(Jacobson 1999, among others)
directly with their antecedents.
Jacobson’s z-shift)
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joe : j λz.z × z : j ⊸ (j ⊗ p) joe × joe : j ⊗ p [x : j]1 λuλq.say(u, q) : j ⊸ b ⊸ s λq.say(x, q) : b ⊸ s [y : p]2 λv.bowl(v) : p ⊸ b bowl(y) : b say(x, bowl(y)) : s
⊗E,1,2
let joe × joe be x × y in say(x, bowl(y)) : s ⇒β say(joe, bowl(joe)) : s
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picking up on a theme from Wednesday’s semantics workshop.
Crouch 2002a,b).
➡ Flexible framework with lots of scope for exploration of questions of compositionality and semantic representation
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