Generative Power of CCGs with Generalized Type-Raised Categories

This paper shows that a class of Combinatory Categorial Grammars (CCGs) augmented with a linguistically-motivated form of type raising involving variables is weakly equivalent to the standard CCGs not involving variables. The proof is based on the idea that any instance of such a granunar can be simulated by a standard CCG

Generative Power of CCGs with Generalized Type-Raised Categories

A type of `non-traditional constituents' motivates an extended class of Combinatory Categorial Grammars (CCG), CCGs with Generalized Type-Raised Categories (CCG-GTRC) involving variables. Although the class of standard CCGs is proved to be equivalent to Linear Indexed Grammars and Tree Adjoining Grammars, use of variables can increase the power beyond these grammars. In order to establish a desired context with respect to computational complexity, this paper shows that there is a subclass of CCG-GTRC which is still weekly equivalent to the standard CCGs. The idea behind the proof is that the behavior of GTRCs can be simulated by appropriately setting the lexicon of a standard CCG. 1 Introduction In Japanese, as in other SOV languages, a sequence of NPs can form a conjunct as exemplified below. (1) John-ga Mary-o , Ken-ga Naomi-o tazuneta. f John-NOM May-ACC g CONJ f Ken-NOM Naomi-ACC g visited "John visited Mary and Ken [visited] Naomi." This type of `non-traditional constituents' po..

Generative Power of CCGs with Generalized Type-Raised Categories

A type of `non-traditional constituents' motivates an extended class of Combinatory Categorial Grammars (CCG), CCGs with Generalized Type-Raised Categories (CCG-GTRC) involving variables. Although the class of standard CCGs is proved to be equivalent to Linear Indexed Grammars and Tree Adjoining Grammars, use of variables can increase the power beyond these grammars. In order to establish a desired context with respect to computational complexity, this paper shows that there is a subclass of CCG-GTRC which is still weekly equivalent to the standard CCGs. The idea behind the proof is that the behavior of GTRCs can be simulated by appropriately setting the lexicon of a standard CCG. 1 Introduction In Japanese, as in other SOV languages, a sequence of NPs can form a conjunct as exemplified below. (1) John-ga Mary-o , Ken-ga Naomi-o tazuneta. f John-NOM May-ACC g CONJ f Ken-NOM Naomi-ACC g visited "John visited Mary and Ken [visited] Naomi." This type of `non-traditional constituents' po..