anchor.diff:    // Simple Operators
     static final TokenType PLUS = const TokenType._internal("PLUS",1);
     static final TokenType MINUS = const TokenType._internal("MINUS",1);
  -  static final TokenType UNMINUS = const TokenType._internal("UNMINUS",1);
  +  static final TokenType UNMINUS = const TokenType._internal("UNMINUS",5);
     static final TokenType TIMES = const TokenType._internal("TIMES",2);
     static final TokenType DIV = const TokenType._internal("DIV",2);
   
     // Complex Operators
  -  static final TokenType POW = const TokenType._internal("POW",3);
  +  static final TokenType POW = const TokenType._internal("POW",4);
     static final TokenType SQRT = const TokenType._internal("SQRT",3);
     static final TokenType LOG = const TokenType._internal("LOG",3);
     static final TokenType LN = const TokenType._internal("LN",3);
  
positive.code:     keywords["e"] = TokenType.EFUNC;
      keywords["("] = TokenType.LBRACE;
      keywords[")"] = TokenType.RBRACE;
      _tokenStream = new List<Token>();
    }
  
    List<Token> get tokenStream =>  _tokenStream;
  
    /**
     * Tokenizes a given input string.
     * Returns a list of [Token] in infix notation.
     */
    List<Token> createTokenStream(String inputString) {
      List<Token> tempTokenStream = new List<Token>();
  
      String clearedString = inputString.replaceAll(" ", "");
  
negative.code:   Token(String this.text, TokenType this.type);
  
    String toString() {
      return "($type,$text)";
    }
  }
  
  