public void TestGetNullable04() {
var productions = new HashSet<Production> {
CFGParser.Production("<A> -> <A> <A>"),
CFGParser.Production("<A> -> ε"),
CFGParser.Production("<A> -> 'a'"),
};
var result = (Dictionary<Nonterminal, double>)nullableClass.InvokeStatic("GetNullable", new object[] { productions });
Assert.IsTrue(result.Count == 1);
var phiRecip = 2.0 / (1.0 + Math.Sqrt(5));
Helpers.AssertNear(1.0 - phiRecip, result[Nonterminal.Of("A")]);
}