public void TestMissingStart01() {
var productions = new List<Production> {
CFGParser.Production(@"<X_0> -> <X_0> <X_0>"),
CFGParser.Production(@"<X_0> -> 'a'"),
};
Grammar g = new Grammar(productions, Nonterminal.Of("S"));
CNFGrammar h = g.ToCNF();
}
private static void ExecuteTest(Grammar g, List<Sentence> sentences) {
CNFGrammar h = g.ToCNF();
var earley = new EarleyParser(g);
var cyk = new CykParser(h);
foreach (var sentence in sentences) {
var p1 = cyk.ParseGetProbability(sentence);
var p2 = earley.ParseGetProbability(sentence);
Helpers.AssertNear(p1, p2);
}
}
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 TestToCNF01() {
var productions = new List<Production> {
CFGParser.Production(@"<X_0> -> 'x3' <X_0> [23]"),
CFGParser.Production(@"<X_0> -> ε [85]"),
};
Grammar g = new Grammar(productions, Nonterminal.Of("X_0"));
CNFGrammar h = g.ToCNF();
Helpers.AssertNear(85.0 / 108.0, h.Cyk(Sentence.FromLetters("")));
Helpers.AssertNear((23.0 / 108.0) * (85.0 / 108.0), h.Cyk(Sentence.FromWords("x3")));
Helpers.AssertNear((23.0 / 108.0) * (23.0 / 108.0) * (85.0 / 108.0), h.Cyk(Sentence.FromWords("x3 x3")));
}
public void TestUnitProductions01() {
var productions = new List<Production> {
CFGParser.Production(@"<S> -> <A> [3]"),
CFGParser.Production(@"<S> -> <B> [1]"),
CFGParser.Production(@"<A> -> 'a'"),
CFGParser.Production(@"<B> -> 'b'"),
};
Grammar g = new Grammar(productions, Nonterminal.Of("S"));
CNFGrammar h = g.ToCNF();
Helpers.AssertNear(0.0, h.Cyk(Sentence.FromLetters("")));
Helpers.AssertNear(0.75, h.Cyk(Sentence.FromLetters("a")));
Helpers.AssertNear(0.25, h.Cyk(Sentence.FromLetters("b")));
}
public void TestCNFNoNull02() {
var productions = new HashSet<Production> {
CFGParser.Production("<A> -> <A>"),
CFGParser.Production("<A> -> 'a'"),
CFGParser.Production("<A> -> 'b'"),
};
Grammar g = new Grammar(productions, Nonterminal.Of("A"));
CNFGrammar h = g.ToCNF();
Helpers.AssertNear(0, h.Cyk(Sentence.FromLetters("")));
Helpers.AssertNear(0.5, h.Cyk(Sentence.FromLetters("a")));
Helpers.AssertNear(0.5, h.Cyk(Sentence.FromLetters("b")));
}
public void TestCFGToCNFBadProb01() {
// S -> aSa | bSb | ε
var productions = new List<Production> {
CFGParser.Production(@"<S> -> 'a' <S> 'a' [1]"),
CFGParser.Production(@"<S> -> 'b' <S> 'b' [3]"),
CFGParser.Production(@"<S> -> ε [4]"),
};
Grammar g = new Grammar(productions, Nonterminal.Of("S"));
CNFGrammar h = g.ToCNF();
Helpers.AssertNear(0.5, h.Cyk(Sentence.FromLetters("")));
Helpers.AssertNear((1.0 / 8) * 0.5, h.Cyk(Sentence.FromLetters("aa")));
Helpers.AssertNear((3.0 / 8) * 0.5, h.Cyk(Sentence.FromLetters("bb")));
Helpers.AssertNear((1.0 / 8) * (3.0 / 8) * 0.5, h.Cyk(Sentence.FromLetters("abba")));
}
public void TestUnitProductions02() {
var g = new Grammar(new List<Production>{
CFGParser.Production("<X_5> → 'x0' [22.103242747999378]"),
CFGParser.Production("<X_5> → <X_4> <X_2> 'x3' 'x3' <X_5> 'x4' <X_5> [13.799233343824387]"),
CFGParser.Production("<X_7> → 'x1' <X_0> 'x3' <X_9> 'x1' 'x0' <X_9> <X_5> [95.444187448566865]"),
CFGParser.Production("<X_7> → ε [92.294680857702474]"),
CFGParser.Production("<X_2> → <X_9> <X_4> [67.541615066370753]"),
CFGParser.Production("<X_9> → <X_0> <X_7> 'x3' <X_4> 'x2' 'x1' 'x3' [36.206671634319555]"),
CFGParser.Production("<X_0> → <X_4> [41.7635276861319]"),
CFGParser.Production("<X_4> → <X_0> [85.572940545423393]"),
CFGParser.Production("<X_4> → <X_9> 'x2' 'x1' <X_9> 'x2' 'x0' [19.93626149694261]"),
CFGParser.Production("<X_0> → 'x3' [13.794410955530783]"),
CFGParser.Production("<X_9> → ε [86.73295911109679]")
}, Nonterminal.Of("X_0"));
var h = g.ToCNF();
}
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 TestToCNF02() {
var productions = new List<Production> {
CFGParser.Production(@"<S> -> 'a' <B> <B>"),
CFGParser.Production(@"<B> -> 'b'"),
CFGParser.Production(@"<B> -> ε"),
};
Grammar g = new Grammar(productions, Nonterminal.Of("S"));
CNFGrammar h = g.ToCNF();
var pa = h.Cyk(Sentence.FromLetters("a"));
var pab = h.Cyk(Sentence.FromLetters("ab"));
var pabb = h.Cyk(Sentence.FromLetters("abb"));
Assert.IsTrue(pa > 0.0);
Assert.IsTrue(pab > 0.0);
Assert.IsTrue(pabb > 0.0);
Helpers.AssertNear(1.0, pa + pab + pabb);
}
public void TestAccepts06() {
var productions = new HashSet<Production> {
CFGParser.Production("<X_3> -> ε"),
CFGParser.Production("<X_2> -> ε"),
CFGParser.Production("<X_0> -> <X_2> <X_1>"),
CFGParser.Production("<X_1> -> <X_3> <X_3>"),
};
var g = new Grammar(productions, Nonterminal.Of("X_0"));
var h = g.ToCNF();
Assert.IsTrue(h.Accepts(Sentence.FromWords("")));
}
public void TestToCNF07() {
Grammar g = new Grammar(new List<Production>{
CFGParser.Production("<X_0> → 'x1' 'x4' <X_2> <X_6> [48.024797111295534]"),
CFGParser.Production("<X_1> → <X_0> 'x0' [28.859845304796398]"),
CFGParser.Production("<X_4> → 'x4' 'x4' 'x4' <X_3> <X_6> [32.396577754708275]"),
CFGParser.Production("<X_4> → ε [46.519217869974312]"),
CFGParser.Production("<X_0> → 'x4' 'x0' 'x3' 'x3' [90.918005973993814]"),
CFGParser.Production("<X_6> → <X_4> <X_0> 'x3' <X_3> [31.319837867431264]"),
CFGParser.Production("<X_2> → <X_2> [72.917730323932]"),
CFGParser.Production("<X_3> → <X_1> [36.901735786302822]"),
CFGParser.Production("<X_6> → ε [40.092343899464396]"),
CFGParser.Production("<X_2> → 'x1' [16.801839537826293]"),
CFGParser.Production("<X_0> → ε [136.892430380868]")
}, Nonterminal.Of("X_0"));
CNFGrammar h = g.ToCNF();
// Helpers.AssertNear(1.0, h.Cyk(Sentence.FromWords("")));
}
public void TestToCNF06() {
Grammar g = new Grammar(new List<Production>{
CFGParser.Production("<S> → ε"),
CFGParser.Production("<S> → 'x' <A>")
}, Nonterminal.Of("S"));
CNFGrammar h = g.ToCNF();
Helpers.AssertNear(1.0, h.Cyk(Sentence.FromWords("")));
}
public void TestToCNF05() {
Grammar g = new Grammar(new List<Production>{
CFGParser.Production("<X_0> → 'x4' <X_4> [16.517998587115667]"),
CFGParser.Production("<X_4> → 'x3' [49.290950734303777]"),
CFGParser.Production("<X_0> → 'x4' 'x1' [23.628313965456705]")
}, Nonterminal.Of("X_0"));
CNFGrammar h = g.ToCNF();
var first = 16.517998587115667;
var third = 23.628313965456705;
var sum = first + third;
Helpers.AssertNear(third / sum, h.Cyk(Sentence.FromWords("x4 x1")));
Helpers.AssertNear(first / sum , h.Cyk(Sentence.FromWords("x4 x3")));
}
public void TestToCNF04() {
var productions = new HashSet<Production> {
CFGParser.Production("<A> -> <A> <B>"),
CFGParser.Production("<A> -> ε"),
CFGParser.Production("<B> -> 'b'"),
CFGParser.Production("<B> -> ε"),
};
Grammar g = new Grammar(productions, Nonterminal.Of("A"));
CNFGrammar h = g.ToCNF();
var third = 1.0 / 3.0;
Helpers.AssertNear(0.5 + third * 0.5, h.Cyk(Sentence.FromLetters("")));
Helpers.AssertNear(third * 2.0 / 3.0, h.Cyk(Sentence.FromLetters("b")));
}
public void TestToCNF03() {
var productions = new HashSet<Production> {
CFGParser.Production("<A> -> <B> <C>"),
CFGParser.Production("<B> -> <C>"),
CFGParser.Production("<B> -> 'b'"),
CFGParser.Production("<B> -> ε"),
CFGParser.Production("<C> -> <B>"),
CFGParser.Production("<C> -> 'c'"),
CFGParser.Production("<C> -> ε"),
};
Grammar g = new Grammar(productions, Nonterminal.Of("A"));
CNFGrammar h = g.ToCNF();
Helpers.AssertNear(0.25, h.Cyk(Sentence.FromLetters("")));
Helpers.AssertNear(0.25, h.Cyk(Sentence.FromLetters("b")));
Helpers.AssertNear(0.25, h.Cyk(Sentence.FromLetters("c")));
Helpers.AssertNear(0.140625, h.Cyk(Sentence.FromLetters("bc")));
Helpers.AssertNear(0.046875, h.Cyk(Sentence.FromLetters("cc")));
Helpers.AssertNear(0.046875, h.Cyk(Sentence.FromLetters("bb")));
Helpers.AssertNear(0.015625, h.Cyk(Sentence.FromLetters("cb")));
}
public void TestAccepts04() {
var productions = new HashSet<Production> {
CFGParser.Production("<X_2> -> <X_3> <X_1>"),
CFGParser.Production("<X_3> -> <X_1> <X_1>"),
CFGParser.Production("<X_0> -> 'x2' 'x0' <X_3> <X_2> <X_2>"),
CFGParser.Production("<X_2> -> 'x0' 'x3' <X_1> 'x0' 'x0'"),
CFGParser.Production("<X_3> -> <X_1>"),
CFGParser.Production("<X_2> -> <X_1> 'x4'"),
CFGParser.Production("<X_1> -> ε"),
CFGParser.Production("<X_0> -> <X_2>"),
CFGParser.Production("<X_1> -> 'x4' <X_2> <X_1> 'x0' 'x1'"),
CFGParser.Production("<X_1> -> <X_2> 'x0' 'x1' <X_2> <X_2>"),
CFGParser.Production("<X_2> -> 'x1' <X_2> 'x3'"),
CFGParser.Production("<X_1> -> <X_3> <X_0> <X_2> <X_3>"),
};
var g = new Grammar(productions, Nonterminal.Of("X_0"));
var h = g.ToCNF();
Assert.IsTrue(h.Accepts(Sentence.FromWords("x2 x0 x0 x3 x0 x0 x4")));
Assert.IsTrue(h.Accepts(Sentence.FromWords("x2 x0 x4 x4")));
Assert.IsTrue(h.Accepts(Sentence.FromWords("x0 x3 x0 x0")));
Assert.IsTrue(h.Accepts(Sentence.FromWords("x2 x0")));
Assert.IsTrue(h.Accepts(Sentence.FromWords("x4")));
}
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 TestProbabilityUnit01() {
var productions = new HashSet<Production> {
CFGParser.Production("<A> -> 'a'"),
CFGParser.Production("<A> -> <B>"),
CFGParser.Production("<B> -> 'b'"),
CFGParser.Production("<B> -> <A>"),
};
var g = new Grammar(productions, Nonterminal.Of("A"));
var h = g.ToCNF();
Helpers.IsNear(2.0 / 3, h.Cyk(Sentence.FromLetters("a")));
Helpers.IsNear(1.0 / 3, h.Cyk(Sentence.FromLetters("b")));
}
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("")));
}
public void TestAccepts07() {
var productions = new HashSet<Production> {
CFGParser.Production("<A> -> 'a'"),
CFGParser.Production("<A> -> <B>"),
CFGParser.Production("<B> -> 'b'"),
CFGParser.Production("<B> -> <A>"),
};
var g = new Grammar(productions, Nonterminal.Of("A"));
var h = g.ToCNF();
Assert.IsTrue(h.Accepts(Sentence.FromWords("a")));
Assert.IsTrue(h.Accepts(Sentence.FromWords("b")));
}
