gistfile1.txt

#prod -> right-hand side one element
nt -> left-hand side non-terminal
count -> true, if prod is in left
  
  def create_prod_combinations(prod, nt, count):
	        numset = 1 << count
	        new_prods = []

	        for i in range(numset):
	            nth_nt = 0
	            new_prod = ''
	            for s in prod:
	                if s == nt:
	                    if i & (1 << nth_nt):
	                        new_prod = new_prod+s
	                    nth_nt += 1
	                else:
	                    new_prod = new_prod+s
	            new_prods.append(new_prod)
	        return new_prods