anchor.diff:      ;
   
   caseCondition
  -    : expressions | isCaseCondition | satisfiesCaseCondition
  +    : expressions 
  +    | isCaseCondition 
  +    | satisfiesCaseCondition
       ;
   
   expressions
  
positive.code:     ;
  
  controlStructure
      : ifElse | switchCaseElse | simpleWhile | doWhile | forFail | tryCatchFinally
      ;
      
  ifElse
  
negative.code:     ;
  
  memberParameters
      : 
          typeParameters? 
          formalParameters+ 
          extraFormalParameters? 
          metatypes? 
          typeConstraints?
      ;
  
  //TODO: should we allow the shortcut style of method
  