MySQL to Postgres question

The table I have in MySQL is similar to below:

0 SET FOREIGN_KEY_CHECKS=0;
1 CREATE TABLE products (
2 product_id integer(11) not null auto_increment,
3 product_name varchar(255) not null,
4 product_descrition varchar(255) not null,
5 class_id integer(11) not null,
6 subclass_id integer(11) not null,
7 department_id integer(11) not null
8 PRIMARY KEY (product_id),
9 KEY class_id (class_id),
10 KEY subclass_id (subclass_id),
11 KEY department_id (department_id)
12 );

When I try and rewrite it as a Postgres statement (below), it fails at line
9.
0 SET CONSTRAINTS ALL DEFERRED;
1 CREATE TABLE products (
2 product_id serial[11] not null,
3 product_name varchar[255] not null,
4 product_descrition varchar[255] not null,
5 class_id integer[11] not null,
6 subclass_id integer[11] not null,
7 department_id integer[11] not null
8 PRIMARY KEY (product_id),
9 KEY class_id (class_id),
10 KEY subclass_id (subclass_id),
11 KEY department_id (department_id)
12 );

Any ideas?