3.1 What are we doing in Syntax?

• We assume that everybody knows about context-free grammars. For example:

  % Rules:
          s  -> np vp
          np -> det n
          vp -> v np
 
% Lexicon:
          n -> man | woman
          v -> likes | knows
          det -> the | a | every       

  We will soon build a bottom-up parser for a context free grammar in Oz.

• Does everybody know what a chart-parser is? If you don't know it then your are probably not studying computational linguistics. Don't worry, we will explain it to you and even built a chart-parser in Oz.

• Unification Grammar = Context-free Grammar + Feature constraints

• We will show to you how to built a chart parser for unification grammars in Oz. This will turn out to be quite simple even though some advanced features of Oz are needed (which are not available in any other language).

• In the last part of this lecture, we will built a parser for a dependency grammar in Oz (if there is enough time). Beside of what you need for unification grammar, this parser makes heavily use of constraint programming with finite domain constraints.