Following up on several discussions of simplex adjustments and ragged arrays of simplexes

It’s been a while but I just wanted to follow up to ask @spinkney what was your source for that specification of log_dirichlet_lpdf? I recently asked about the RNG version of this and Bob Carpenter pointed out that it looks like there is a stray log_theta[N] term. His math looks correct to me so I just want to make sure I’m not overlooking something important.