how to generate a list of distinct scalar values from a column which type is array

Dear all, <br /><br />given a column which type is for instance varchar(20)[], is there any SQL command that let me
generatethe list of distinct scalar values? <br /><br /><br />e.g.: <br />             col1<br />row 1: (aaa, bb, c)
<br/>row 2: (dddd, eeee) <br />row 3: (aaa, eeee) <br /><br />the query should return: <br /><br />aaa <br />bb <br />c
<br/>dddd <br />eeee <br /><br />if not, I guess the approach is to use stored procedure. Any code
snippet/suggestion?<br/><br />Thanks, Sergio <br /><br />