The Context Free Grammar Checker
  1. For checking the basic properties of context free grammar: first sets, follow sets, cyclicity, left recursion, LL(1), LR(0), SLR(1), LALR(1), LR(1).
  2. For transforming the grammar: left recursion removal, factoring, reachability, realizability, follow set clash removal, LR(0)-state annotation for LALR(1) ⇒ SLR(1) transformation.
Programming Languages Laboratory,
Department of Computer Science
University of Calgary



NEW: the next version of the context-free grammar checker is in development and available for use. Please send comments and bug reports to and