anchor.diff:  
   // https://msdn.microsoft.com/en-us/library/ms187742.aspx
   column_definition
  -    : column_name (data_type | AS expression) null_notnull?
  +    : column_name (data_type | AS expression) (COLLATE id)? null_notnull?
         ((CONSTRAINT constraint=id)? DEFAULT constant_expression (WITH VALUES)?
          | IDENTITY ('(' seed=DECIMAL ',' increment=DECIMAL ')')? (NOT FOR REPLICATION)?)?
         ROWGUIDCOL?
  
positive.code:     ;
  
  procedure_param
      : LOCAL_ID (id '.')? data_type VARYING? ('=' default_val=default_value)? (OUT | OUTPUT | READONLY)?
      ;
  
  procedure_option
  
negative.code: 
  // 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)? ';'?
      ;
  
  // https://msdn.microsoft.com/en-us/library/ms187956.aspx
  