anchor.diff:  	: DOLLAR_DUMPPORTSLIMIT LEFT_PARENTHESIS file_size COMMA file_pathname RIGHT_PARENTHESIS SEMICOLON
   	;
   
  -file_size
  -	: DECIMAL_NUMBER
  -	;
  -
   // 18.3.5 Reading dump file during simulation ($dumpportsflush)
   
   dumpportsflush_task
   	: DOLLAR_DUMPPORTSFLUSH LEFT_PARENTHESIS file_pathname RIGHT_PARENTHESIS SEMICOLON
   	;
   
  -// 18.4 Format of extended VCD file
  -// 18.4.1 Syntax of extended VCD file
  -
  -value_change_dump_definitions
  -	: declaration_command* simulation_command*
  -	;
  -
  -declaration_command
  -	: declaration_keyword COMMAND_TEXT? DOLLAR_END
  -	;
  -
  -simulation_command
  -	: simulation_keyword VALUE_CHANGE* DOLLAR_END
  -	;
  -
  -declaration_keyword
  -	: DOLLAR_COMMENT
  -	| DOLLAR_DATE
  -	| DOLLAR_ENDDEFINITIONS
  -	| DOLLAR_SCOPE
  -	| DOLLAR_TIMESCALE
  -	| DOLLAR_UPSCOPE
  -	| DOLLAR_VAR
  -	| DOLLAR_VCDCLOSE
  -	| DOLLAR_VERSION
  -	;
  -
  -simulation_keyword
  -	: DOLLAR_DUMPPORTS
  -	| DOLLAR_DUMPPORTSOFF
  -	| DOLLAR_DUMPPORTSON
  -	| DOLLAR_DUMPPORTSALL
  -	;
  -*/
   // A.1 Source text
   // A.1.1 Library source text
   
  
positive.code: 	| DOLLAR_ATAN2
  	| DOLLAR_HYPOT
  	;
  /*
  // 18. Value change dump (VCD) files
  // 18.3 Creating extended VCD file
  // 18.3.1 Specifying dump file name and ports to be dumped ($dumpports)
  
  
negative.code: 	;
  
  file_pathname
  	: STRING
  	| variable_identifier
  	| expression
  	;
  
  // 18.3.2 Stopping and resuming the dump ($dumpportsoff/$dumpportson)
  