public void TestParsing04() {
var g = new Grammar(new List<Production>{
CFGParser.Production("<X_0> → <X_2> 'x2' 'x0'"),
CFGParser.Production("<X_2> → <X_0>"),
CFGParser.Production("<X_0> → 'x1'"),
CFGParser.Production("<X_2> → 'q'")
}, Nonterminal.Of("X_0"));
var sentences = new List<Sentence>();
sentences.Add(Sentence.FromWords("x1 x2 x0 x2 x0"));
ExecuteTest(g, sentences);
}