anchor.diff:                      new Token("(", TokenType.LBRACE),
                       new Token("100", TokenType.VAL),
                       new Token(")", TokenType.RBRACE)];
  -    
  +
       tokenStream3 = [new Token("log", TokenType.LOG),
  +                    new Token("(", TokenType.LBRACE),
                       new Token("10", TokenType.VAL),
  -                    new Token("100", TokenType.VAL)];
  +                    new Token(")", TokenType.RBRACE),
  +                    new Token("(", TokenType.LBRACE),
  +                    new Token("100", TokenType.VAL),
  +                    new Token(")", TokenType.RBRACE)];
     }
  -  
  -  
  -
  -  
   
     /*
      *  Tests and variables.
      */
  -
     Parser pars;
     Lexer lex;
     String inputString1;
     String inputString2;
     String inputString3;
  -  
  +
     List<Token> tokenStream1;
     List<Token> tokenStream2;
     List<Token> tokenStream3;
   
     List<Token> upnTokenStream1;
     List<Token> upnTokenStream2;
  -  
  -  
  -  void parserTokenTest(){
  +
  +
  +  void parserTokenTest() {
       List<Token> stream1 = lex.createTokenStream(inputString1);
       List<Token> stream2 = lex.createTokenStream(inputString2);
       List<Token> stream3 = lex.createTokenStream(inputString3);
   
       List<Token> upnStream1 = lex.shuntingYard(stream1);
       List<Token> upnStream2 = lex.shuntingYard(stream2);
  -   
  -    
  +
       expect(stream1, orderedEquals(tokenStream1));
       expect(stream1, isNot(orderedEquals(tokenStream2)));
       expect(stream2, orderedEquals(tokenStream2));
       expect(stream2, isNot(orderedEquals(tokenStream1)));
       expect(stream3, orderedEquals(tokenStream3));
  -
  -  }
  -  
  -void parserExpressionTest(){
  -    
     }
   
  -  
  +  void parserExpressionTest() {
  +    throw new UnimplementedError();
  +  }
  +
  +
   }
positive.code:   void initTests() {
      pars = new Parser();
      lex = new Lexer();
      inputString1 = "x + 2";
      inputString3 = "log(10)(100)";
      
      tokenStream1 = new List<Token>();
      tokenStream1.add(new Token("x", TokenType.VAR));
      tokenStream1.add(new Token("+", TokenType.PLUS));
      tokenStream1.add(new Token("2", TokenType.VAL));
      
      inputString2 = "x * 2^2.5 * log(10)(100)";
      tokenStream2 = [new Token("x", TokenType.VAR),
                      new Token("*", TokenType.TIMES),
                      new Token("2", TokenType.VAL),
  
negative.code:                     new Token("(", TokenType.LBRACE),
                      new Token("100", TokenType.VAL),
                      new Token(")", TokenType.RBRACE)];
  
      upnTokenStream2 = [new Token("x", TokenType.VAR),
                      new Token("*", TokenType.TIMES),
                      new Token("2", TokenType.VAL),
  