Notes on computational linguistics.pdf - UCLA Department of ...

Stabler - Lx 185/209 2003
Extra credit: Jurafsky and Martin (1999, p503) present the following four semantic representations for the
sentence Ihaveacar:
First order predicate calculus:
∃x,y Having(x) ∧ Haver(Speaker,x)∧ HadT hing(y, x) ∧ Car(y)
Frame-based representation:
Having
Haver: Speaker
HadThing: Car
Conceptual dependency diagram:
Semantic network:
Haver
Speaker
Car
⇑poss-by
Speaker
Having
Had−Thing
They say (p502)“…there are a number of significant differences among these four approaches to representation…”
but then later they say of the latter three representations (p539) “It is now widely accepted
that meanings represented in these approaches can be translated into equivalent statements in [first order
predicate calculus] with relative ease.”
Contrasting with all of these representations, our representation of “I have -s a car” is just its derivation:
CP
C’
C TP
DP(1)
D’
[I]
D
T
t
V
[have]
T’
DP
t(1)
v
v
v
vP
T
[-s]
[a]
v’
D
DP(0)
D’
VP
NumP
Num’
Num NP
N’
N
[car]
V
t
V’
DP
t(0)
[(ɛ,ɛ,[I,have,-s,a,car]):[C]]
Car
[ɛ::[=T,C]] [([I],ɛ,[have,-s,a,car]):[T]]
[(ɛ,ɛ,[have,-s,a,car]):[+(k),T],(ɛ,[I],ɛ):[-(k)]]
[[-s]::[v==>,+(k),T]] [(ɛ,[have],[a,car]):[v],(ɛ,[I],ɛ):[-(k)]]
[(ɛ,[have],[a,car]):[=D,v]]
[ɛ::[=>V,=D,v]] [([a,car],[have],ɛ):[V]]
256
[(ɛ,[have],ɛ):[+(k),V],(ɛ,[a],[car]):[-(k)]]
[[I]::[D,-(k)]]
[[have]::[=D,+(k),V]] [(ɛ,[a],[car]):[D,-(k)]]
[[a]::[=Num,D,-(k)]] [(ɛ,ɛ,[car]):[Num]]
[ɛ::[=N,Num]] [[car]::[N]]