docs: public void add(Rule rule) {
  		List<Token> tokens = rule.getTokens();
  		for (Token token : tokens) {
  			for (String str : token.getTerms()) {
  				if (str.charAt(0) != ':') {
  					Library.insertWord(forest, new Value(str, "rule", "10000"));
  				}
  			}
  		}
  
  
  		for (String str : tokens.get(0).getTerms()) {
  			Set<Rule> rules = ruleIndex.get(str);
  			if(rules==null){
  				rules = new HashSet<>() ;
  				ruleIndex.put(str,rules) ;
  			}
  			rules.add(rule) ;
  		}
  	}