This paper describes an algorithm for computing optimal structural descriptions for Optimality Theory grammars with context-free position structures. This algorithm extends Tesar's dynamic programming approach (Tesar, 1994) (Tesar, 1995a) to computing optimal structural descriptions from regular to context-free structures. The generalization to contextfree structures creates several complicatio...

We associate a boundary $\mathcal B_{\pi ,u}$ to each covariant representation $(\pi ,u,H)$ of $C^*$-dynamical system $(G,A,\alpha )$ and study the action $G$ on its amenability properties. relate rigidity properties traces associated crossed product $C^*$-algebra faithfulness group this boundary.