Grammar induction of Context Free Languages seems to be a very well researched field. I would like to know the current state of the art in inducing a Context Free Grammar (I am reading up Higuera's Grammatical Inference book, and looking through previous papers). What is the current bound on inducing a Context Free Grammar given unstructured (non parenthesized) input?
In particular, I would like to know the community's opinion on the paper by Bastani et al. Synthesizing Program Input Grammars. How it compares to existing work. Does it improve the algorithmic bounds?