Computational perspectives on minimalism

While research in ‘principles and parameters’ tradition [18] can be regarded as attributing as much as possible to universal grammar (UG) in order to understand how language acquisition is possible, Chomsky characterizes the ‘minimalist program’ as an effort to attribute as little as possible to UG while still accounting for the apparent diversity of human languages [23, p.4]. Of course, these two research strategies aim to be compatible, and ultimately should converge. Several of Chomsky’s own early contributions to the minimalist program have been fundamental and simple enough to allow easy mathematical and computational study. Among these contributions are (1) the characterization of ‘bare phrase structure,’ and (2) the definition of a structure building operation merge which applies freely to lexical material, with constraints that ‘filter’ the results only at the PF and LF interfaces. The first studies inspired by (1) and (2) are ‘stripped down’ to such a degree that they may seem unrelated to minimalist proposals, but in this paper, we show how some easy steps begin to bridge the gap. This paper briefly surveys some proposals about (3) syntactic features that license structure building, (4) ‘locality,’ the domain over which structure building functions operate, (5) ‘linearization’, determining (in part) the order of pronounced forms, and (6) the proposal that merge sometimes involves ‘copies.’ Two very surprising, overarching results emerge. First, seemingly diverse proposals are revealed to be remarkably similar, often defining identical languages, with recursive mechanisms that are similar (Thms. 25, below). As noted by Joshi [47] and others, this remarkable convergence extends across linguistic traditions and even to mathematical work that started with very different assumptions and goals (Thm. 1, below). Second, all the mechanisms reviewed here define sets of structures with nice computational properties; they all define ‘abstract families of languages’ (AFLs) that are efficiently recognizable. This raises an old puzzle: why would human languages have properties that guarantee the existence of parsing methods that correctly and efficiently identify all and only the well-formed sentences, when humans apparently do not use methods of that kind? A speculation – perhaps supported by the whole cluster of AFL properties – is that this