Query-ing arrays

Stupid FAQ probably:

Is it possible to query an array for an item WITHOUT KNOWING where in the
array the item might be held?

For example, I have a tbale with the following character array:
> category char(3)[],

I would like to find all records in which 'category' contains an array
element of a certain type, like maybe 'xxx' for instance. So, for a
particular record, 'category' may be set to '{'gfe','qwe','xcs','xxx'}'

I cannot do:
SELECT * FROM blah WHERE category[4]='xxx';
because I do not know that the 'xxx' will always be in the 4th position.

Suggestions? TIA, Jon

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Jon Lapham
Centro Nacional de Ressonancia Magnetica Nuclear de Macromoleculas
Universidade Federal do Rio de Janeiro (UFRJ) - Brasil
email: jlapham(at)gandalf(dot)bioqmed(dot)ufrj(dot)br
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