anchor.diff:         )*)?
         RPAREN                {params = (String[]) paramList.toArray(new String[]{});}
       ;
  -
   
   //---------------------------------------------------------------------------
   private specialSymbol returns[String text]
  
positive.code: 
  //---------------------------------------------------------------------------
  private definition
      : opDefinition;
  
  private opDefinition
  {
  
negative.code:     ;
  
  //---------------------------------------------------------------------------
  private sortDeclarationOrDefinition returns[ElementFactory.Item sort]
  {
      sort = null;
      String[] params = null;
      String name = null;
      String sortDef = null;
  }
      : begin:"sort" 
        name=qualifiableNames
        ((formalSortParameters) => 
              (params=formalSortParameters) (equals sortDef=sort)?
            | (equals sortDef=sort)?
        )
                             {sort = builder.createSort(name, params);
                               ParserUtil.setBounds(builder, sort, begin, LT(0));
                              }
      ;
  