anchor.diff:  arguments 
       : positionalArguments | namedArguments
       ;
  -      
  +    
   namedArgument
       : parameterName specifier /*(',' assignable)**/ ';'
       ;
  
positive.code: 
  functorType
      : functorHeader formalParameters
      ;
  
  annotations
  
negative.code:     | 'null'
      | 'none'
      | inlineClassDeclaration
      ;
  
  enumeration
  