Parikh's theorem: A simple and direct automaton construction
Parikh's theorem states that the Parikh image of a context-free language is semilinear or, equivalently, that every context-free language has the same Parikh image as some regular language. We present a very simple construction that, given a context-free grammar, produces a finite automaton recognizing such a regular language. (C) 2011 Elsevier B.V. All rights reserved.
parikh image context-free language regular language formal languages