public void TestAccepts03()
{
var productions = new HashSet <Production> {
CFGParser.Production("<S> -> <S> <S> <S>"),
CFGParser.Production("<S> -> ε"),
CFGParser.Production("<S> -> 'x2' 'x0'"),
CFGParser.Production("<S> -> 'x0' <S>"),
CFGParser.Production("<S> -> 'x4'"),
CFGParser.Production("<S> -> <S> 'x0' 'x4'"),
CFGParser.Production("<S> -> 'x3' <S> 'x3' <S> 'x0'"),
CFGParser.Production("<S> -> 'x2' <S> <S> <S> <S>"),
CFGParser.Production("<S> -> <S> <S> <S> <S> <S>"),
CFGParser.Production("<S> -> 'x0' <S> <S>"),
CFGParser.Production("<S> -> <S>"),
CFGParser.Production("<S> -> 'x0' <S> <S> 'x1'"),
CFGParser.Production("<S> -> 'x3' 'x2' 'x1'"),
CFGParser.Production("<S> -> 'x0' 'x0' 'x2'"),
};
Grammar g = new Grammar(productions, Nonterminal.Of("S"));
CNFGrammar h = g.ToCNF();
Assert.IsTrue(h.Accepts(Sentence.FromLetters("")));
Assert.IsTrue(h.Accepts(Sentence.FromWords("x4")));
Assert.IsTrue(h.Accepts(Sentence.FromWords("x4 x0 x4")));
}
public void TestFreshNames()
{
var productions = new List <Production> {
CFGParser.Production(@"<S> -> 'a'"),
CFGParser.Production(@"<X_0> -> 'b'"),
};
Grammar g = new Grammar(productions, Nonterminal.Of("S"));
CNFGrammar h = g.ToCNF();
Assert.IsTrue(h.Accepts(Sentence.FromLetters("a")));
Assert.IsFalse(h.Accepts(Sentence.FromLetters("b")));
}
public void TestAccepts02()
{
var productions = new HashSet <Production> {
CFGParser.Production("<X_0> -> <X_0> 'x4' <X_0> 'x0'"),
CFGParser.Production("<X_0> -> <X_0> <X_0> 'x2' <X_0> 'x3'"),
CFGParser.Production("<X_0> -> <X_0> 'x1' <X_0>"),
CFGParser.Production("<X_0> -> <X_0> 'x1' 'x1' 'x1' 'x3'"),
CFGParser.Production("<X_0> -> ε"),
};
Grammar g = new Grammar(productions, Nonterminal.Of("X_0"));
CNFGrammar h = g.ToCNF();
Assert.IsTrue(h.Accepts(Sentence.FromLetters("")));
Assert.IsTrue(h.Accepts(Sentence.FromWords("x4 x0")));
Assert.IsTrue(h.Accepts(Sentence.FromWords("x4 x0 x4 x2 x3 x0")));
}
public void TestAccepts09()
{
var productions = new HashSet <Production> {
CFGParser.Production("<S> -> ε"),
// CFGParser.Production("<S> -> 'x'"),
CFGParser.Production("<S> -> <S> <S> <S>"),
};
Grammar g = new Grammar(productions, Nonterminal.Of("S"));
CNFGrammar h = g.ToCNF();
Assert.IsTrue(h.Accepts(Sentence.FromLetters("")));
}