CREATE OPERATOR $name$ (
    {FUNCTION|PROCEDURE} = $function_name$
    [, LEFTARG = $left_type$ ] [, RIGHTARG = $right_type$ ]
    [, COMMUTATOR = $com_op$ ] [, NEGATOR = $neg_op$ ]
    [, RESTRICT = $res_proc$ ] [, JOIN = $join_proc$ ]
    [, HASHES ] [, MERGES ] )