1. CIS 630 Slides for March 3 2010

2. Schedule We missed two classes. I will try to make up in April Spring break– Week of March 8 Your presentations I would like to have at least 3 presentations decided this week. I will make some suggestions today. Class on March 17 Qiuye Zhao will talk on minimalist grammar—a quick intro, with some discussion, about an hour in all.

3. Plan for today and March17 and 24 (not including your short presentations) I will continue with the following topics -- Reminder of the overall objective -- Some examples to finish the discussion of categorial grammars -- Return to LTAG * Some important extensions * Features and unification * Automaton Dependency Grammars Complexity of Language– Theoretical and Empirical

4. Study a few seemingly diverse systems keeping the following perspective in mind How does one evaluate (prove?) the significance (necessity) of a construct used in the specification of a grammar formalism -- Eliminate it and see whether you can do everything you could do before Some of the constructs are -- Structure: Trees, Acyclic graphs, Sets of trees… Should a sentence be covered by a single structure or a set of structures, …? -- Labels: Terminals, Non-terminals, empty nodes -- Features: atomic, attribute-value pairs, bounded or recursive, how is feature checking done, etc. ….

5. Syntactic Constituents and Semantic Types -- Not identical in all phrase structure type systems -- Identical in categorial systems/grammars Consider John likes in John likes apples * In a CG John likes has a syntactic type as well as a semantic type, S/NP (NP -> S) * In In a TAG John likes has a semantic type, NP-> S but not a syntactic type In a CG coordination is done by a schema X and X = X Exercise: Give a CG analysis for (a) John thinks Mary and Bill believes Harry will win Note that John thinks Mary and Bill believes Harry, both will have to be reduced to S/(S\NP) Exercise: John likes apples and Bill pears Hint: Reduce the left conjunct to S and then decompose it into S/(S\NP)/NP (S\NP)/NP