anchor.diff:        assignableExpression & assignmentOperator & expression
         | conditionalExpression & cascadeSection.star()
         | throwExpression
  -      | rethrowExpression
       ;
   
   
  
positive.code: 
      forStatement = FOR & lparen & forLoopParts & rparen & statement;
      ifStatement = IF & lparen & expression & rparen & statement & (ELSE & statement).optional();
      localFunctionDeclaration = functionSignature & functionBody;
      localVariableDeclaration = initializedVariableDeclaration & semicolon;
      expressionStatement = expression.optional() & semicolon;
  
negative.code:     ;
      functionExpression = formalParameterList & functionExpressionBody;
  
      throwExpression = THROW & expression;
      throwExpressionWithoutCascade = THROW & expressionWithoutCascade;
  
  