Conditional operators ALL, ANY in WHERE clause

Hi

The following is the quote describing WHERE clause of SELECT
(pgsql/doc/html/sql-select.html).

"WHERE Clause 

The optional WHERE condition has the general form: 

WHERE boolean_expr   

boolean_expr can consist of any expression which evaluates to a boolean value. In many cases,
this expression will be: 
    expr cond_op expr   

or 
    log_op expr   

where cond_op can be one of: =, <, <=, >, >= or <>, a conditional operator like ALL, ANY, IN,
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
LIKE, or a locally defined operator, and log_op can be one of: AND, OR, NOT. SELECT will ignore
all rows for which the WHERE condition does not return TRUE. "

Please give me hints how can I use "conditional operators ALL, ANY" in
WHERE clause.

Some examples will be appreciated.

Thanks in advance.

-- 
Vladimir Zolotych                         gsmith@eurocom.od.ua