#ifndef grr_nonempty_H
#define grr_nonempty_H
/* grr_nonempty.c - procedures for removing empty strings from the grammar */
/* Last edited on 2024-12-21 11:47:08 by stolfi */

#include <vec.h>
#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>

#include <grr_grammar.h>

Grammar_t *grr_remove_empty_rules(Grammar_t *G);
/*
  Given an arbitrary grammar {G}, returns an almost-equivalent
  empty-free grammar {G1}. The new grammar {G1} has the same symbols
  as {G}, but (1) every symbol generates the same terminal strings as
  in {G}, except the empty string; (2) every derivation tree in {G1}
  is a derivation tree of {G} with a non-empty terminal phrase, 
  with all subtrees leading to the empty string deleted. */

#endif