anchor.diff:  	| specify_block
   	| attribute_instance* parameter_declaration ';'
   	| attribute_instance* specparam_declaration
  +	| in_module_compiler_directive
   	;
   
   parameter_override
  
positive.code: 	;
  
  ifdef_group_of_lines
  	: non_port_module_item*
  	;
  
  ifndef_group_of_lines
  	: non_port_module_item*
  	;
  
  elsif_group_of_lines
  	: non_port_module_item*
  	;
  
  else_group_of_lines
  	: non_port_module_item*
  	;
  
  // 19.5 `include
  
negative.code: 	| attribute_instance* system_task_enable
  	| attribute_instance* task_enable
  	| attribute_instance* wait_statement
  	| in_module_compiler_directive
  	;
  
  statement_or_null
  