Well-Nestedness Properly Subsumes Strict Derivational Minimalism

Makoto Kanazawa (1) , Jens Michaelis (2) , Sylvain Salvati (3, 4) , Ryo Yoshinaka (5)

1 NII - National Institute of Informatics
2 Universität Bielefeld = Bielefeld University
3 Inria Bordeaux - Sud-Ouest
4 LaBRI - Laboratoire Bordelais de Recherche en Informatique
5 Graduate School of Informatics [Kyoto]

Minimalist grammars (MGs) constitute a mildly context-sensitive formalism when being equipped with a particular locality condition (LC), the shortest move condition. In this format MGs define the same class of derivable string languages as multiple context-free grammars (MCFGs). Adding another LC to MGs, the specifier island condition (SPIC), results in a proper subclass of derivable languages. It is rather straightforward to see this class is embedded within the class of languages derivable by some well-nested MCFG (MCFG wn ). In this paper we show that the embedding is even proper. We partially do so adapting the methods used in [13] to characterize the separation of MCFG wn -languages from MCFG-languages by means of a "simple copying" theorem. The separation of strict derivational minimalism from well-nested MCFGs is then characterized by means of a "simple reverse copying" theorem. Since for MGs, well-nestedness seems to be a rather ad hoc restriction, whereas for MCFGs, this holds regarding the SPIC, our result may suggest we are concerned here with a structural difference between MGs and MCFGs which cannot immediately be overcome in a non-stipulated manner.

Domaines: Informatique et langage [cs.CL]

Makoto Kanazawa, Jens Michaelis, Sylvain Salvati, Ryo Yoshinaka. Well-Nestedness Properly Subsumes Strict Derivational Minimalism. Logical Aspects of Computational Linguistics - 6th international conference, 2011, Montpellier, France. pp.112-128. ⟨hal-00959629⟩