public void TestParsing07() {
var g = new Grammar(new List<Production>{
CFGParser.Production("<A> → <B>"),
CFGParser.Production("<B> → <C>"),
CFGParser.Production("<C> → <B>"),
CFGParser.Production("<B> → <A>"),
CFGParser.Production("<B> → 'x'"),
}, Nonterminal.Of("A"));
var sentences = new List<Sentence>();
sentences.Add(Sentence.FromWords("x"));
ExecuteTest(g, sentences);
}