Lexicalized Tree-Adjoining Grammars (LTAG) - ad-teaching.infor...
Lexicalized Tree-Adjoining Grammars (LTAG) - ad-teaching.infor...
Lexicalized Tree-Adjoining Grammars (LTAG) - ad-teaching.infor...
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Lexicalization<br />
Example (CFG which is not strongly lexicalizable with a TSG)<br />
Consider the following CFG:<br />
An intuitive approach to lexicalize<br />
it with a TSG might be:<br />
S → SS<br />
S → a<br />
S<br />
a<br />
S↓<br />
S<br />
S<br />
S<br />
S<br />
S↓<br />
But this is not a strong lexicalization<br />
because it cannot generate the following<br />
tree (which the CFG can generate):<br />
S<br />
a<br />
S<br />
a<br />
S<br />
S<br />
S<br />
S<br />
S<br />
Problem: In TSGs the distance between two nodes in the same<br />
initial tree cannot increase during derivation.<br />
a<br />
a<br />
a<br />
a<br />
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