anchor.diff:  
   // https://msdn.microsoft.com/en-us/library/ms174979.aspx
   create_table
  -    : CREATE TABLE table_name '(' column_def_table_constraint (',' column_def_table_constraint)* ','? ')' (ON id | DEFAULT)? ';'?
  +    : CREATE TABLE table_name '(' column_def_table_constraint (','? column_def_table_constraint)* ','? ')' (ON id | DEFAULT)? ';'?
       ;
   
   // https://msdn.microsoft.com/en-us/library/ms187956.aspx
  
positive.code:     : table_name_with_hint        as_table_alias?
      | rowset_function             as_table_alias?
      | derived_table              (as_table_alias column_alias_list?)?
      | function_call               as_table_alias?
      | LOCAL_ID                    as_table_alias?
      | LOCAL_ID '.' function_call (as_table_alias column_alias_list?)?
      ;
  
  // https://msdn.microsoft.com/en-us/library/ms191472.aspx
  join_part
  
negative.code:     ;
  
  procedure_param
      : LOCAL_ID (id '.')? AS? data_type VARYING? ('=' default_val=default_value)? (OUT | OUTPUT | READONLY)?
      ;
  
  procedure_option
  