ERDF forms problem

From n² wiki

The question is, how to add eRDF (with any necessary liberties with syntax) to this form, and parse it, so that the $selected array can be populated with "Cheese" and "Switzerland"

//data triples
<#x> dc:subject "Cheese","Switzerland" .

//php

$selected = array('Cheese','Switzerland');

$selects = array(
'Cheese' => 'Cheese',
'Switzerland' => 'Switzerland',
'Hotels' => 'Hotels',
);

//html

<form>
	<select multiple="multiple">
	<?php foreach($selects as $option => $value):?>
		<option 
			<?php if(in_array($value, $selected)):?>selected="selected"<?php endif>
			value="<?=$value?>"
			><?=$option?></option>
	<?php endforeach?>
	</select>
</form>