Well-Nestedness Properly Subsumes Strict Derivational Minimalism

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.