/**
* A more restrictive phrase-structure grammar, used in testing and demonstrating
* the CYK Algorithm.
* Note: It is complemented by the "trivial lexicon" in LexiconExamples.java
* @return
*/
public static ProbCNFGrammar buildTrivialGrammar()
{
ProbCNFGrammar g = new ProbCNFGrammar();
ICollection <Rule> rules = CollectionFactory.CreateQueue <Rule>();
rules.Add(new Rule("S", "NP,VP", (float)1.0));
rules.Add(new Rule("NP", "ARTICLE,NOUN", (float)0.50));
rules.Add(new Rule("NP", "PRONOUN,ADVERB", (float)0.5));
rules.Add(new Rule("VP", "VERB,NP", (float)1.0));
// add terminal rules
Lexicon trivLex = LexiconExamples.buildTrivialLexicon();
ICollection <Rule> terminalRules = CollectionFactory.CreateQueue <Rule>(trivLex.getAllTerminalRules());
rules.AddAll(terminalRules);
// Add all these rules into the grammar
if (!g.addRules(rules))
{
return(null);
}
return(g);
}
/**
* An elementary Chomsky-Normal-Form grammar for simple testing and
* demonstrating. This type of grammar is seen more in Computing Theory classes,
* and does not mock a subset of English phrase-structure.
* @return
*/
public static ProbCNFGrammar buildExampleGrammarOne()
{
ProbCNFGrammar g = new ProbCNFGrammar();
ICollection <Rule> rules = CollectionFactory.CreateQueue <Rule>();
// Start Rules
rules.Add(new Rule("S", "Y,Z", (float)0.10));
rules.Add(new Rule("B", "B,D", (float)0.10));
rules.Add(new Rule("B", "G,D", (float)0.10));
rules.Add(new Rule("C", "E,C", (float)0.10));
rules.Add(new Rule("C", "E,H", (float)0.10));
rules.Add(new Rule("E", "M,N", (float)0.10));
rules.Add(new Rule("D", "M,N", (float)0.10));
rules.Add(new Rule("Y", "E,C", (float)0.10));
rules.Add(new Rule("Z", "E,C", (float)0.10));
// Terminal Rules
rules.Add(new Rule("M", "m", (float)1.0));
rules.Add(new Rule("N", "n", (float)1.0));
rules.Add(new Rule("B", "a", (float)0.25));
rules.Add(new Rule("B", "b", (float)0.25));
rules.Add(new Rule("B", "c", (float)0.25));
rules.Add(new Rule("B", "d", (float)0.25));
rules.Add(new Rule("G", "a", (float)0.50));
rules.Add(new Rule("G", "d", (float)0.50));
rules.Add(new Rule("C", "x", (float)0.20));
rules.Add(new Rule("C", "y", (float)0.20));
rules.Add(new Rule("C", "z", (float)0.60));
rules.Add(new Rule("H", "u", (float)0.50));
rules.Add(new Rule("H", "z", (float)0.50));
// Add all these rules into the grammar
if (!g.addRules(rules))
{
return(null);
}
return(g);
}