anchor.diff:      ;
   
   specificationOrExpressionStatement
  -    : primary specifier? ';'!
  +    : expression specifier? ';'!
       ;
   
   directiveStatement
  
positive.code: formalParameter
      : basicFormalParameter
        ( '->' type parameterName 
        | (('in'|'=') formalParameterStart) => ('in'|'=') basicFormalParameter
        )? 
        specifier?
      ;
      
  basicFormalParameter
      : annotations? formalParameterType parameterName formalParameters*
      ;
  
negative.code: //be careful with this one, since it 
  //matches "()", which can also be an 
  //argument list
  formalParametersStart
      : '(' ( annotatedDeclarationStart | ')' )
      ;
      
  // FIXME: This accepts more than the language spec: named arguments
  