Complexity and Determinism in Linguistic Computation Phases and Cartography in Phrase Structure Building

Developing linguistic resources (such as lexica, grammars etc.) that can be used both in parsing and in generation is an extremely difficult task. Nonetheless, thinking about this option is useful in order to highlight properties of the linguistic competence that seem to be cognitively motivated. The standard minimalist approach (Chomsky 1995-2001) sketches a model that does not fit in any clear way with specific performance algorithms such as parsing or generation even though much emphasis is put on “interface properties”. The grammar formalized in these pages (based on Stabler 1997) keeps into account some important constraints posed both by the generation and by the parsing problems, eventually defining a model that is: a. usable both in parsing and in generation; b. cognitively motivated; c. tractable; d. mainly deterministic. In particular, to achieve these results, I will focus on three important properties: 1. structure building operations (an algorithm specification for building phrases) can be included as part of the grammar if they apply top-to-bottom, from left-to-right; 2. using a Linearization Principle (inspired by Kayne’s LCA, Kayne 1994) and fixing the functional structure by means of a universal hierarchy (cartographic approach, Belletti ed. 2002, Cinque 1999, ed. 2002, Rizzi 1997, ed. 2002 and related works) makes the algorithm mainly deterministic; 3. formalizing phases (Chomsky 1999) helps us making the algorithm (that should deal at least with ambiguities and long distance relations) tractable; A plausible conclusion we could draw from these results is that these properties are not only cognitively plausible, but also formally and computationally more than welcome.