TRALE
TRALE
CSC485/2501
November 26, 2021
∣∣∣ Computer Science
November 26, 2021 1 / 8
Outline
Semantics vs agreement
SubCat
Gap and Movement
Semantic head driven generation
(Beta reduction and quantifier)
November 26, 2021 2 / 8
Semantics vs agreement
SubCat
Gap and Movement
Semantic head driven generation
(Beta reduction and quantifier)
November 26, 2021 3 / 8
The Active Voice
The goalie kicked the ball.
S
VP
NP
the ball
theme
V
kicked
NP
The goalie
agent
sem:(kick, agent:goalie, theme:ball)
November 26, 2021 4 / 8
The Passive Voice
The ball was kicked.
S
VP
VP
NP
ε
V
kicked
aux
was
NP
The ball
theme
sem:(kick, agent:?, theme:ball)
November 26, 2021 5 / 8
The Passive Voice
The ball was kicked.
S (gap)
VP (gap)
VP (gap)
NP
ε
V
kicked
aux
was
NP
The ball
theme
sem:(kick, agent:?, theme:ball)
November 26, 2021 6 / 8
Semantic Head Driven Generation: TLDR
TLDR: Replace cat> with sem head> on all the semantic heads.
An NP’s semantic head is the N.
A VP’s semantic head is the V.
A CLP semantic head is the CL.
An S semantic head is the VP.
November 26, 2021 7 / 8
Semantic Head Driven Generation: Basic Idea
gen(s, sem:(kick, agent:goalie, theme:ball)).
Top-down or buttom-up generator: too slow to traverse all of the possible rules.
However, we can utilize the fact that the semantics (sem) of the semantic head is
exactly the same as the product (left hand side).
November 26, 2021 8 / 8