Since constituents exhibits richer appearances than contexts, the proposed Bayesian prior over α ij,pq |B ij,pq is more complicate than that over β ij,pq |B ij,pq .
one of the non-parametric Bayesian priors, the Pitman-Yor-Process (PYP) prior, is defined on α ij,pq |B ij,pq .