Consider the following RTN from Allen 1987, p. 51:
In this figure, only the NP arc is a "push" arc; all others are "cat" or "pop" arcs. The numbers on the arcs indicate the order in which arcs will be tried when more than one arc leaves a node.
Use the following lexicon:
| Category | Word |
|---|---|
| art | a, the |
| number | one |
| pronoun | one |
| adj | green, wild |
| noun | dogs, green, man, saw |
| verb | broke, cried, faded, man, saw, |
(a) Using the RTN parser handout, show a trace in the format I demonstrated in lecture of a top-down RTN parse of the following sentence:
(b) Implement this RTN and lexicon in SNaLPS, and run it using (parse 4). Compare the results with your answer to part (a).
Map the following CFG into an equivalent RTN that uses only three networks: S, NP, and PP. (Just draw the RTN; you don't have to implement it in SNaLPS.)
S -> NP VP
S -> NP VP PREPS
NP -> Art NominalP
NP -> NominalP
NominalP -> N
NominalP -> Adj Nominal
NominalP -> Nominal PREPS
Nominal -> N
PREPS -> PP
PREPS -> PP PREPS
PP -> Prep NP
VP -> V
VP -> V NP
VP -> V PREPS