anchor.diff:  assignmentExpression
       :   conditionalExpression
       |   unaryExpression assignmentOperator assignmentExpression
  +    |   DigitSequence // for
       ;
   
   assignmentOperator
  
positive.code:     |   directDeclarator '[' typeQualifierList? '*' ']'
      |   directDeclarator '(' parameterTypeList ')'
      |   directDeclarator '(' identifierList? ')'
      ;
  
  gccDeclaratorExtension
  
negative.code:     ;
  
  iterationStatement
      :   While '(' expression ')' statement
      |   Do statement While '(' expression ')' ';'
      |   For '(' forCondition ')' statement
      ;
  
  //    |   'for' '(' expression? ';' expression?  ';' forUpdate? ')' statement
  //    |   For '(' declaration  expression? ';' expression? ')' statement
  
  forCondition
  	:   forDeclaration ';' forExpression? ';' forExpression?
  	|   expression? ';' forExpression? ';' forExpression?
  	;
  
  forDeclaration
      :   declarationSpecifiers initDeclaratorList
  	| 	declarationSpecifiers
      ;
  
  forExpression
      :   assignmentExpression
      |   forExpression ',' assignmentExpression
      ;
  
  jumpStatement
  