Notation of index

Hi,

I'm moving from MySQL to Pg.
MySQL lets me create indices like this:

CREATE TABLE t (
id INTEGER NOT NULL,
numba INTEGER NOT NULL,
txt VARCHAR(100) NOT NULL,
anosanumba INTEGER NOT NULL ,

PRIMARY KEY (id),
INDEX (numba),
UNIQUE (anosanumba)
);

PostgreSQL doesn't like the line :
INDEX (numba),

Instead I have to use :
CREATE INDEX idx_t_numba ON t (numba);
outside the CREATE TABLE statement.
And as far as I understand I do have to give an plain INDEX explicitely
a name while Pg makes one up for the UNIQUE.

The point is, that I want to use foreign keys and I figure it helped if
those fk-columns were indexed but PG won't create indices for columns in
fk-constraints automatically.
Am I right ?

Why can we use INDEX the same way as UNIQUE ?
Perhaps even as in
...
numba INT4 NOT NULL INDEX
...