anchor.diff:  
   numeric_function
      : SUM '(' (DISTINCT | ALL)? expression ')'
  -   | COUNT '(' ( '*' | ((DISTINCT | UNIQUE | ALL)? concatenation)? ) ')' over_clause?
  +   | COUNT '(' ( ASTERISK | ((DISTINCT | UNIQUE | ALL)? concatenation)? ) ')' over_clause?
      | ROUND '(' expression (',' UNSIGNED_INTEGER)?  ')'
      | AVG '(' (DISTINCT | ALL)? expression ')'
      | MAX '(' (DISTINCT | ALL)? expression ')'
  
positive.code:     ;
  
  using_clause
      : USING ('*' | (','? using_element)+)
      ;
  
  using_element
  
negative.code:     ;
  
  query_block
      : SELECT (DISTINCT | UNIQUE | ALL)? (ASTERISK | (','? selected_element)+)
        into_clause? from_clause where_clause? hierarchical_query_clause? group_by_clause? model_clause?
      ;
  
  