in category, not in generation

$tax_query = array(
	'relation' => 'AND',
	array(
		'taxonomy'         => 'category',
		'operator'         => 'EXISTS',
	),
	array(
		'taxonomy'         => 'generation',
		'operator'         => 'EXISTS',
	),
	array(
		'taxonomy'         => 'awards',
		'operator'         => 'EXISTS',
	),
);