where n c,e represents the expected count of rule c → e, and K is the total number of ways to rewrite c, we now take into account our DP(α c , P 0 (• | c)) prior in (1), which, when truncated to a finite grammar, reduces to a K-dimensional Dirichlet prior with parameter α c P 0 (• | c).
in VB we perform a variational E-step with the subprobabilities given by where Ψ denotes the digamma function.