anchor.diff:      |   functionDeclaration
       |   propGetDeclaration
       |   propLhsDeclaration
  +    |   RemStatement
       |   implementsDirective
       ;
   
  
positive.code:     |   optionBaseDirective
      |   optionExplicitDirective
      |   optionPrivateDirective 
      |   implementsDirective
      |   defDirective
      |   variableDeclaration
  
negative.code: statementLabel              :   identifier | lineNumberLabel;
  statementLabelList          :   statementLabel (',' statementLabel);
  lineNumberLabel             :   IntegerLiteral;  // actually can only be a decimal literal.
  
  // 5.4.1.2 Rem Statement
  // converted to lexer rule.
  
  // 5.4.2 Control Statements
  controlStatement            
  