On the trees underlying natural language sentences
Colloquium in Honor of Gérard Huet, Paris 22-23 June 2007
We address the old question which lead to formal language theory:
which formal grammars generates natural language sentences?
We will first survey the linguistic hypotheses
and formal studies which lead to the description of sentences
as the strings produced by mildly context sensitive grammars.
In order to interpret sentences one needs to assign to them some
structure, usually trees and sometimes graphs. I will survey the
current knowledge on theses classes of trees before presenting a
result by Kobele, Salvati and Ithe present author inspired by the two
step approach to natural language formalisms of Michaelis, Mönnich and
Morawietz: the parse trees produced by minimalist grammars, a
mildly-context-sensitive formalism introduced by Stabler, can be
described as the image by some tree transducer of a regular tree