anchor.diff:    | HASH LPAREN mintypmax_expression RPAREN
     ;
   
  -clocking_drive
  -  : clockvar_expression LT_EQ cycle_delay? expression
  +clocking_drive_statement
  +  : clockvar_expression LT_EQ cycle_delay expression SEMI
     ;
   
   clockvar
  
positive.code:   ;
  
  statement_expression
    : expression LT_EQ delay_or_event_control? expression  // non-blocking assignment
    | expression EQ delay_or_event_control expression      // blocking assignment
    | expression EQ dynamic_array_new                      // dynamic array init
    | expression EQ class_new                              // object init
  
negative.code:   | seq_block
    | wait_statement
    | procedural_assertion_statement
    | clocking_drive_statement
    | randsequence_statement
    | randcase_statement
    | expect_property_statement
  